CN118412659A - Wide incident angle frequency selection structure with high pass and steep cut-off - Google Patents

Abstract

The present invention discloses a high-pass, steep-cutoff wide-incident-angle frequency selection structure. The structure includes a first and a second selection component arranged vertically interlaced with each other, and the first and the second selection components each include a dielectric substrate with a slot and a meander-shaped conductive geometric structure and a C-shaped conductive geometric structure on the two surfaces of the dielectric substrate, and the conductive geometric structures are interconnected through conductive metal vias. The present invention can realize a high-pass filtering function for space electromagnetic waves below 5 GHz, in any polarization direction, and within a wide incident angle range of 0 to 60 degrees, and the transition band between the passband and the stopband is very narrow, with a steep cutoff effect; the present invention also solves the limitations of the prior art in narrow passband bandwidth, transition bandwidth between passband and stopband, and narrow incident angle range, and is easy to process and manufacture, and can be widely used in antenna covers of communication base stations, radars, satellite communications, and aircraft platforms.

Description

A high-pass, steep-cutoff frequency-selective structure with wide incident angle

Technical Field

The invention relates to an angular frequency selection structure, to the fields of spatial filtering technology and antenna technology, and in particular to a high-pass, steep-cutoff, wide-incident-angle frequency selection structure.

Background technique

As a spatial filter, the frequency selective structure can select and regulate electromagnetic waves in space according to the operating frequency, polarization mode, incident angle and energy of the electromagnetic waves. Different from the traditional filter, the frequency selective structure is a passive array, and its excitation source is not a voltage or current signal source, but electromagnetic waves in space. The frequency selective structure is usually an artificial electromagnetic structure periodic array composed of metal patches (or slotted apertures on a metal screen) and dielectric materials designed according to certain rules. It exhibits the characteristics of total reflection or total transmission of electromagnetic waves in space near the resonant frequency. Thanks to this unique ability to select and regulate electromagnetic waves, the frequency selective structure has a wide range of applications in electromagnetic compatibility, suppressing electromagnetic interference, improving antenna system performance, and reducing radar scattering cross-sectional area.

Generally, multi-band antennas are integrated in modern communication systems to increase the capacity of the communication system, which poses a great challenge to the performance of the frequency selective structure. Not only does it require an ultra-wide passband frequency selective structure to cover the operating frequency bands of all antennas, but it also requires a fast cutoff rate and stopband suppression to suppress out-of-band interference. Existing research results are difficult to achieve ultra-wide passband, steep cutoff of low-frequency stopband, and wide incident angle performance at the same time. Therefore, how to achieve a frequency selective structure with ultra-wide passband, steep cutoff, and wide incident angle is an urgent problem to be solved.

Summary of the invention

In order to solve the problems existing in the background technology, the present invention provides a high-pass, steep-cutoff wide-incident-angle frequency selection structure. It can simultaneously achieve ultra-wide passband, steep cutoff and wide-incident-angle performance of low-frequency stopband. The present invention can filter space electromagnetic waves below 5GHz, in any polarization direction, and within a wide incident angle range of 0 to 60 degrees. The transition band between the passband and the stopband is very narrow, and has a steep cutoff effect. It has great application value in modern communications, radars, military defense and other fields.

The technical solution adopted by the present invention is:

The high-pass, steep-cutoff, wide-incident-angle frequency selection structure of the present invention comprises a plurality of rectangular plate-shaped first selection components that are evenly spaced and arranged in parallel with each other, and a plurality of rectangular plate-shaped second selection components that are evenly spaced and arranged in parallel with each other, wherein each first selection component and each second selection component are orthogonal to each other and are vertically interlaced to form a mortise and tenon fitting structure; both side surfaces of each first selection component are divided into a plurality of rectangular first conductive geometric structure printed areas along its own length direction, and each first conductive geometric structure printed area is printed with the same first conductive geometric structure; both side surfaces of each second selection component are divided into a plurality of rectangular second conductive geometric structure printed areas along its own length direction, and each second conductive geometric structure printed area is printed with the same second conductive geometric structure; each first conductive geometric structure printed area is interlaced between two adjacent second selection components, and each second conductive geometric structure area is interlaced between two adjacent first selection components.

The first selection component is a first dielectric substrate with a plurality of first slots arranged at intervals. The first slots are strip-shaped through slots that penetrate the plate surface of the first dielectric substrate and are parallel to the width direction of the first dielectric substrate. A first slot is provided in each first conductive geometric structure printing area on the first dielectric substrate. Each first slot is located between two adjacent first conductive geometric structures. The length direction of the first conductive geometric structure printing area is parallel to the width direction of the first dielectric substrate. Each first slot is provided from one of the short side vertices of the first conductive geometric structure printing area to the center of the long side of the first conductive geometric structure printing area. Each first conductive geometric structure on one side of the first dielectric substrate is flipped half a circle along the central axis of the length direction of the first conductive geometric structure printing area where it is located, and then overlaps with the first conductive geometric structure on the other side opposite to it. The first conductive geometric structures and the first slots in each first conductive geometric structure printing area are periodically arranged on both sides of the first dielectric substrate along the length direction of the first dielectric substrate.

The second selection component is a second dielectric substrate with a plurality of second slots arranged at intervals, the second slots are strip-shaped through slots penetrating the plate surface of the second dielectric substrate and parallel to the width direction of the second dielectric substrate, a second slot is provided in each second conductive geometric structure printing area on the second dielectric substrate, each second slot is located between two adjacent second conductive geometric structures, the length direction of the second conductive geometric structure printing area is parallel to the width direction of the second dielectric substrate, each second slot is opened from one of the short side vertices of the second conductive geometric structure printing area to the center of the long side of the second conductive geometric structure printing area, each second conductive geometric structure on one side of the second dielectric substrate is flipped half a circle along the central axis of the length direction of the second conductive geometric structure printing area where it is located, and then overlaps with the second conductive geometric structure on the other side opposite to it; the second conductive geometric structures and second slots in each second conductive geometric structure printing area are periodically arranged along the length direction of the second dielectric substrate on both sides of the second dielectric substrate.

When each first selection component and each second selection component are orthogonal to each other, each first groove on each first selection component is interlaced perpendicularly with a second groove on each second selection component in turn. When each second selection component and each first selection component are orthogonal to each other, each second groove on each second selection component is interlaced perpendicularly with a first groove on each first selection component in turn.

The first conductive geometric structure includes a meandering spiral conductive geometric structure and a C-shaped conductive geometric structure. The first conductive geometric structure printing areas on both side surfaces of the first dielectric substrate are opposite to each other. The first conductive geometric structure printing area on one side surface of the first dielectric substrate is printed with the first meandering spiral conductive geometric structure and the first C-shaped conductive geometric structure, and the first conductive geometric structure printing area on the other side surface of the first dielectric substrate is printed with the second meandering spiral conductive geometric structure and the second C-shaped conductive geometric structure.

The C-shaped conductive geometric structure is formed by a rectangular sheet-like conductive structure with wider widths on both sides and a rectangular strip-like conductive structure with narrower widths in the middle, thereby forming a three-section right-angle bent C-shaped structure. The width direction of the rectangular sheet-like conductive structures on both sides of the C-shaped conductive geometric structure and the length direction of the rectangular strip-like conductive structure in the middle are both parallel to the length direction of the first conductive geometric structure printing area. The rectangular strip-like conductive structure is close to one side of the long side of the first conductive geometric structure printing area and is located on the side of the first slot in the first conductive geometric structure printing area away from itself. The rectangular sheet-like conductive structures on both sides of the C-shaped conductive geometric structure are provided with right-angle bent serpentine slots, and the openings at both ends of the right-angle bent serpentine slots are both located on the symmetry axis in the length direction of the first conductive geometric structure printing area. The four vertices of the C-shaped conductive geometric structure are connected to form a rectangle and are provided with conductive metal vias that penetrate the board surface of the first dielectric substrate in sequence. The fifth conductive metal via and the sixth conductive metal via are located between two adjacent first slots. The C-shaped conductive geometric structures on both sides of the first dielectric substrate are connected through the conductive metal vias.

The meandering spiral conductive geometric structure is located in the middle of the C-shaped conductive geometric structure, one end of the meandering spiral conductive geometric structure is located on the central axis of the length direction of the first slot of the first conductive geometric structure printing area where the meandering spiral conductive geometric structure is located and is close to the first slot, the other end of the meandering spiral conductive geometric structure is located at the center of the first conductive geometric structure printing area, one end of the meandering spiral conductive geometric structure is first printed along the width direction of the first conductive geometric structure printing area, then bent at a right angle toward the direction close to the first slot, and then printed in a right-angle spiral shape to the other end, and the two ends of the meandering spiral conductive geometric structure are respectively provided with conductive metal vias that penetrate the board surface of the first dielectric substrate, the first conductive metal via is located in the center of the first conductive geometric structure printing area, the meandering spiral conductive geometric structures on both sides of the first dielectric substrate are connected through the first conductive metal via, the second conductive metal via is close to the first slot, and the first meandering spiral conductive geometric structure on one side of the first dielectric substrate and a second meandering spiral conductive geometric structure that is not directly opposite to it but adjacent to it on the other side of the first dielectric substrate are connected through the second conductive metal via.

The second conductive geometric structure includes a meandering spiral conductive geometric structure and a C-shaped conductive geometric structure. The second conductive geometric structure printing areas on both side surfaces of the second dielectric substrate are opposite to each other. A third meandering spiral conductive geometric structure and a third C-shaped conductive geometric structure are printed on the second conductive geometric structure printing area on one side surface of the second dielectric substrate. A fourth meandering spiral conductive geometric structure and a fourth C-shaped conductive geometric structure are printed on the second conductive geometric structure printing area on the other side surface of the second dielectric substrate.

The C-shaped conductive geometric structure is formed by a rectangular sheet-like conductive structure with wider widths on both sides and a rectangular strip-like conductive structure with narrower widths in the middle, thereby forming a three-section right-angle bent C-shaped structure. The width direction of the rectangular sheet-like conductive structures on both sides of the C-shaped conductive geometric structure and the length direction of the rectangular strip-like conductive structure in the middle are both parallel to the length direction of the second conductive geometric structure printing area. The rectangular strip-like conductive structure is close to one long side of the second conductive geometric structure printing area and is located on the side of the second slot in the second conductive geometric structure printing area away from itself. The rectangular sheet-like conductive structures on both sides of the C-shaped conductive geometric structure are provided with right-angle bent serpentine slots, and the openings at both ends of the right-angle bent serpentine slots are both located on the symmetry axis in the length direction of the second conductive geometric structure printing area. The four vertices of the C-shaped conductive geometric structure are connected to form a rectangle and are provided with conductive metal vias that penetrate the board surface of the second dielectric substrate in sequence. The ninth conductive metal via and the tenth conductive metal via are located between two adjacent second slots. The C-shaped conductive geometric structures on both sides of the second dielectric substrate are connected through the conductive metal vias.

The meandering spiral conductive geometric structure is located in the middle of the C-shaped conductive geometric structure, one end of the meandering spiral conductive geometric structure is located on the central axis of the length direction of the second groove of the second conductive geometric structure printing area where the meandering spiral conductive geometric structure is located and is close to the second groove, the other end of the meandering spiral conductive geometric structure is located at the center of the second conductive geometric structure printing area, one end of the meandering spiral conductive geometric structure is first printed along the width direction of the second conductive geometric structure printing area, then bent at a right angle in the direction close to the second groove, and then printed in a right-angle spiral shape to the other end, and both ends of the meandering spiral conductive geometric structure are respectively provided with conductive metal vias that penetrate the board surface of the second dielectric substrate, the seventh conductive metal via is located in the center of the second conductive geometric structure printing area, the meandering spiral conductive geometric structures on both sides of the second dielectric substrate are connected through the seventh conductive metal via, the eighth conductive metal via is close to the second groove, and the third meandering spiral conductive geometric structure on one side of the second dielectric substrate and a fourth meandering spiral conductive geometric structure that is not directly opposite to it but adjacent to it on the other side of the second dielectric substrate are connected through the eighth conductive metal via.

When the first slot of the first dielectric substrate and the second slot of the second dielectric substrate intersect each other, the second conductive metal via on the first dielectric substrate and the eighth conductive metal via on the second dielectric substrate are respectively located on both sides of the center point of the width side of the dielectric substrate.

The length of the first slot of the first dielectric substrate and the second slot of the second dielectric substrate is 1/2 of the total width of the dielectric substrate, and the width of the first slot and the second slot is slightly wider than the thickness of the dielectric substrate.

The number of spiral turns of the meandering spiral conductive geometric structure is 1.25 to 1.5 turns.

The serpentine slot of the C-shaped conductive geometric structure has two bending times.

Application of the high-pass, steep-cutoff, wide-incident-angle frequency selection structure of the present invention: Application of the high-pass, steep-cutoff, wide-incident-angle frequency selection structure in a radome.

Application of the high-pass, steep-cutoff, wide-incident-angle frequency selection structure of the present invention: Application of the high-pass, steep-cutoff, wide-incident-angle frequency selection structure in a device for improving isolation between antennas in an antenna system.

The beneficial effects of the present invention are:

The present invention can realize high-pass filtering function for space electromagnetic waves below 5GHz, in any polarization direction and within a wide incident angle range of 0 to 60 degrees, and the transition band between the passband and the stopband is very narrow. Under the condition of less than 2dB insertion loss, the relative fractional bandwidth of the passband is as high as 93.3%, and under the condition of 13dB suppression, the transition band between the passband and the stopband is only 0.13GHz, which has a steep cutoff effect. The present invention also solves the limitations of the prior art of narrow passband bandwidth, transition bandwidth between passband and stopband, and narrow incident angle range, and is easy to process and manufacture, and can be widely used in antenna covers of communication base stations, radars, satellite communications, and aircraft platforms.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG1 is a three-dimensional schematic diagram of a high-pass, steep-cutoff, wide-incident-angle frequency selection structure provided by the present invention;

FIG2 is a partial structural schematic diagram of the A surface of the first selection component in the high-pass, steep-cutoff wide-incident-angle frequency selection structure;

FIG3 is a partial structural diagram of the first selection component B surface in the high-pass, steep-cutoff wide-incident-angle frequency selection structure;

FIG4 is a partial structural diagram of the A surface of the second selection component in the high-pass, steep-cutoff wide-incident-angle frequency selection structure;

FIG5 is a partial structural diagram of the second selection component B surface in the high-pass, steep-cutoff wide-incident-angle frequency selection structure;

FIG6 is a schematic diagram of the transmission coefficient of a preferred embodiment of a high-pass, steep-cutoff wide-incident-angle frequency selection structure under a transverse electric (TE) mode when the electromagnetic wave incident angles are 0°, 30°, and 60°;

FIG7 is a schematic diagram of the transmission coefficient of a preferred embodiment of a high-pass, steep-cutoff wide-incident-angle frequency selection structure in a transverse magnetic (TM) mode when the electromagnetic wave incident angles are 0°, 30°, and 60°;

In the figure: a first selection component 10, a first dielectric substrate 11, a first meander spiral conductive geometric structure 1A2, a second meander spiral conductive geometric structure 1B2, a first C-shaped conductive geometric structure 1A3, a second C-shaped conductive geometric structure 1B3, a first conductive metal via 14, a second conductive metal via 15, a third conductive metal via 16, a fourth conductive metal via 17, a fifth conductive metal via 18, a sixth conductive metal via 19, a second selection component 20, a second dielectric substrate 21, a third meander spiral conductive geometric structure 2A2, a fourth meander spiral conductive geometric structure 2B2, a third C-shaped conductive geometric structure 2A3, a fourth C-shaped conductive geometric structure 2B3, a seventh conductive metal via 24, an eighth conductive metal via 25, a ninth conductive metal via 26, a tenth conductive metal via 27, an eleventh conductive metal via 28, and a twelfth conductive metal via 29.

Detailed ways

The present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

As shown in FIG1 , the high-pass, steep-cutoff, wide-incident-angle frequency selection structure of the present invention comprises a plurality of rectangular plate-shaped first selection components 10 evenly spaced and arranged in parallel with each other, and a plurality of rectangular plate-shaped second selection components 20 evenly spaced and arranged in parallel with each other, each first selection component 10 and each second selection component 20 being orthogonal to each other and vertically interlaced to form a mortise and tenon joint structure; both side surfaces of each first selection component 10 are divided into a plurality of rectangular first conductive geometric structure printed areas along its own length direction, and each first conductive geometric structure printed area is printed with the same first conductive geometric structure; both side surfaces of each second selection component 20 are divided into a plurality of rectangular second conductive geometric structure printed areas along its own length direction, and each second conductive geometric structure printed area is printed with the same second conductive geometric structure; each first conductive geometric structure printed area is interlaced between two adjacent second selection components 20, and each second conductive geometric structure area is interlaced between two adjacent first selection components 10.

The first selection component 10 is a first dielectric substrate 11 with a plurality of first slots arranged at intervals. The first slots are strip-shaped through slots penetrating the plate surface of the first dielectric substrate 11 and are parallel to the width direction of the first dielectric substrate 11. A first slot is provided in each first conductive geometric structure printing area on the first dielectric substrate 11. Each first slot is located between two adjacent first conductive geometric structures. The length direction of the first conductive geometric structure printing area is parallel to the width direction of the first dielectric substrate 11. Each first slot is provided from one of the short side vertices of the first conductive geometric structure printing area to the center of the long side of the first conductive geometric structure printing area. Each first conductive geometric structure on one side of the first dielectric substrate 11 is flipped half a circle along the central axis of the length direction of the first conductive geometric structure printing area where it is located, and then overlaps with the first conductive geometric structure on the other side opposite to it. The first conductive geometric structures and the first slots in each first conductive geometric structure printing area are periodically arranged along the length direction of the first dielectric substrate 11 on both sides of the first dielectric substrate 11.

The second selection component 20 is a second dielectric substrate 21 with a plurality of second slots arranged at intervals. The second slots are strip-shaped through slots penetrating the plate surface of the second dielectric substrate 21 and are parallel to the width direction of the second dielectric substrate 21. A second slot is provided in each second conductive geometric structure printing area on the second dielectric substrate 21. Each second slot is located between two adjacent second conductive geometric structures. The length direction of the second conductive geometric structure printing area is parallel to the width direction of the second dielectric substrate 21. Each second slot is provided from one of the short side vertices of the second conductive geometric structure printing area to the center of the long side of the second conductive geometric structure printing area. Each second conductive geometric structure on one side of the second dielectric substrate 21 is flipped half a circle along the central axis of the length direction of the second conductive geometric structure printing area where it is located, and then overlaps with the second conductive geometric structure on the other side opposite to it. The second conductive geometric structures and second slots in each second conductive geometric structure printing area are periodically arranged along the length direction of the second dielectric substrate 21 on both sides of the second dielectric substrate 21.

When each first selection component 10 and each second selection component 20 are orthogonal to each other, each first groove on each first selection component 10 is interlaced vertically with a second groove on each second selection component 20 in turn. When each second selection component 20 and each first selection component 10 are orthogonal to each other, each second groove on each second selection component 20 is interlaced vertically with a first groove on each first selection component 10 in turn.

As shown in FIGS. 2 and 3 , the first conductive geometric structure includes meandering spiral conductive geometric structures 1A2 and 1B2 and C-shaped conductive geometric structures 1A3 and 1B3. The first conductive geometric structure printing areas on both sides of the first dielectric substrate 11 are opposite to each other. The first conductive geometric structure printing area on one side of the first dielectric substrate 11 is printed with the first meandering spiral conductive geometric structure 1A2 and the first C-shaped conductive geometric structure 1A3. The first conductive geometric structure printing area on the other side of the first dielectric substrate 11 is printed with the second meandering spiral conductive geometric structure 1B2 and the second C-shaped conductive geometric structure 1B3.

The C-shaped conductive geometric structures 1A3 and 1B3 are formed by integrating the wider rectangular sheet-like conductive structures on both sides and the narrower rectangular strip-like conductive structures in the middle to form three right-angle bent C-shaped structures. The width direction of the rectangular sheet-like conductive structures on both sides of the C-shaped conductive geometric structures 1A3 and 1B3 and the length direction of the rectangular strip-like conductive structures in the middle are parallel to the length direction of the first conductive geometric structure printed area. The rectangular strip-like conductive structures are close to the long side of one side of the first conductive geometric structure printed area and are located on the side away from the first slot in the first conductive geometric structure printed area where they are located. The two sides of the C-shaped conductive geometric structures 1A3 and 1B3 The rectangular sheet-like conductive structures on the sides are provided with right-angle bent serpentine grooves, and the openings at both ends of the right-angle bent serpentine grooves are both located on the symmetry axis in the length direction of the first conductive geometric structure printing area. The four vertices of the C-shaped conductive geometric structures 1A3 and 1B3 are connected to form a rectangle and are sequentially provided with conductive metal vias 16, 17, 18, and 19 that pass through the board surface of the first dielectric substrate 11. The fifth conductive metal via 18 and the sixth conductive metal via 19 are located between two adjacent first grooves. The C-shaped conductive geometric structures 1A3 and 1B3 on both sides of the first dielectric substrate 11 are connected through the conductive metal vias 16, 17, 18, and 19.

The meandering spiral conductive geometric structures 1A2 and 1B2 are located in the middle of the C-shaped conductive geometric structures 1A3 and 1B3. One end of the meandering spiral conductive geometric structures 1A2 and 1B2 is located on the central axis of the length direction of the first groove of the first conductive geometric structure printing area where the meandering spiral conductive geometric structures 1A2 and 1B2 are located and close to the first groove. The other end of the meandering spiral conductive geometric structures 1A2 and 1B2 is located in the center of the first conductive geometric structure printing area. One end of the meandering spiral conductive geometric structures 1A2 and 1B2 is first printed along the width direction of the first conductive geometric structure printing area, then bent at a right angle toward the direction close to the first groove, and then printed in a right-angle spiral shape to the other end. Conductive metal vias 14 and 15 penetrating the surface of the first dielectric substrate 11 are respectively provided at both ends of the geometric structures 1A2 and 1B2. The first conductive metal via 14 is located at the center of the first conductive geometric structure printing area. The meandering spiral conductive geometric structures 1A2 and 1B2 on both sides of the first dielectric substrate 11 are connected through the first conductive metal via 14. The second conductive metal via 15 is close to the first slot. The first meandering spiral conductive geometric structure 1A2 on one side of the first dielectric substrate 11 and a second meandering spiral conductive geometric structure 1B2 on the other side of the first dielectric substrate 11 that is not directly opposite to it but adjacent to it are connected through the second conductive metal via 15.

As shown in Figures 4 and 5, the second conductive geometric structure includes meandering spiral conductive geometric structures 2A2, 2B2 and C-shaped conductive geometric structures 2A3, 2B3. The second conductive geometric structure printing areas on both sides of the second dielectric substrate 21 are opposite to each other. The third meandering spiral conductive geometric structure 2A2 and the third C-shaped conductive geometric structure 2A3 are printed on the second conductive geometric structure printing area on one side of the second dielectric substrate 21, and the fourth meandering spiral conductive geometric structure 2B2 and the fourth C-shaped conductive geometric structure 2B3 are printed on the second conductive geometric structure printing area on the other side of the second dielectric substrate 21.

The C-shaped conductive geometric structures 2A3 and 2B3 are formed by integrating the wider rectangular sheet-like conductive structures on both sides and the narrower rectangular strip-like conductive structures in the middle to form three right-angle bent C-shaped structures. The width direction of the rectangular sheet-like conductive structures on both sides of the C-shaped conductive geometric structures 2A3 and 2B3 and the length direction of the rectangular strip-like conductive structures in the middle are parallel to the length direction of the second conductive geometric structure printed area. The rectangular strip-like conductive structures are close to the long side of one side of the second conductive geometric structure printed area and are located on the side away from the second groove in the second conductive geometric structure printed area where they are located. The two sides of the C-shaped conductive geometric structures 2A3 and 2B3 The rectangular sheet-like conductive structures on the sides are provided with right-angle bent serpentine grooves, and the openings at both ends of the right-angle bent serpentine grooves are both located on the symmetry axis in the length direction of the second conductive geometric structure printing area. The four vertices of the C-shaped conductive geometric structures 2A3 and 2B3 are connected to form a rectangle and are sequentially provided with conductive metal vias 26, 27, 28, and 29 that penetrate the plate surface of the second dielectric substrate 21. The ninth conductive metal via 26 and the tenth conductive metal via 27 are located between two adjacent second grooves. The C-shaped conductive geometric structures 2A3 and 2B3 on both sides of the second dielectric substrate 21 are connected through the conductive metal vias 26, 27, 28, and 29.

The meandering spiral conductive geometric structures 2A2 and 2B2 are located in the middle of the C-shaped conductive geometric structures 2A3 and 2B3. One end of the meandering spiral conductive geometric structures 2A2 and 2B2 is located on the central axis of the length direction of the second groove of the second conductive geometric structure printing area where the meandering spiral conductive geometric structures 2A2 and 2B2 are located and close to the second groove. The other end of the meandering spiral conductive geometric structures 2A2 and 2B2 is located in the center of the second conductive geometric structure printing area. One end of the meandering spiral conductive geometric structures 2A2 and 2B2 is first printed along the width direction of the second conductive geometric structure printing area, then bent at a right angle toward the direction close to the second groove, and then printed in a right-angle spiral shape to the other end. Conductive metal vias 24 and 25 penetrating the surface of the second dielectric substrate 21 are respectively provided at both ends of the geometric structures 2A2 and 2B2. The seventh conductive metal via 24 is located at the center of the second conductive geometric structure printing area. The meandering spiral conductive geometric structures 2A2 and 2B2 on both sides of the second dielectric substrate 21 are connected through the seventh conductive metal via 24. The eighth conductive metal via 25 is close to the second slot. The third meandering spiral conductive geometric structure 2A2 on one side of the second dielectric substrate 21 and a fourth meandering spiral conductive geometric structure 2B2 on the other side of the second dielectric substrate 21 that is not directly opposite to it but adjacent to it are connected through the eighth conductive metal via 25.

When the first slot of the first dielectric substrate 11 and the second slot of the second dielectric substrate 21 intersect each other, the second conductive metal via 15 on the first dielectric substrate 11 and the eighth conductive metal via 25 on the second dielectric substrate 21 are located on both sides of the center point of the width side of the dielectric substrates 11 and 21 respectively.

The length of the first slot of the first dielectric substrate 11 and the second slot of the second dielectric substrate 21 is 1/2 of the total width of the dielectric substrates 11 and 21 , and the width of the first slot and the second slot is slightly wider than the thickness of the dielectric substrates 11 and 21 .

The number of spiral turns of the meander-shaped spiral conductive geometric structures 1A2, 1B2, 2A2, and 2B2 is 1.25 to 1.5 turns.

The serpentine slots of the C-shaped conductive geometric structures 1A3, 1B3, 2A3, and 2B3 have two bends.

The specific embodiments of the present invention are as follows:

The slots on the dielectric substrates 11 and 21 in the first selection component 10 and the second selection component 20 of the high-pass, steep-cutoff, wide-incident-angle frequency selection structure provided in this embodiment and the conductive geometric structures on the two surfaces of the dielectric substrates 11 and 21 are arranged periodically with a period of 4 mm.

The total width of the dielectric substrates 11 and 21 in the first selection component 10 and the second selection component 20 of the high-pass, steep-cutoff, wide-incident-angle frequency selection structure provided in this embodiment is 30 mm, the thickness of the dielectric substrates 11 and 21 is 0.2 mm, the length of the slot is 1/2 of the total width of the dielectric substrates 11 and 21, that is, 15 mm, the width of the slot is slightly wider than the thickness of the dielectric substrates 11 and 21, and is 0.2 mm to 0.22 mm, specifically 0.22 mm, the dielectric constant of the dielectric substrates 11 and 21 is 3.1, and the loss tangent is 0.0028.

The number of spiral turns of the zigzag spiral conductive geometric structures 1A2, 1B2, 2A2, and 2B2 on the two surfaces of the dielectric substrates 11 and 21 of the high-pass, steep-cutoff, wide-incident-angle frequency selective structure provided in this embodiment is 1.25 to 1.5 turns, specifically 1.25 turns, the line width of the zigzag spiral conductive geometric structures 1A2, 1B2, 2A2, and 2B2 is 0.2 mm, and the spacing between the spiral turns is 0.4 mm.

The conductive metal patches on both sides of the C-shaped conductive geometric structures 1A3, 1B3, 2A3, 2B3 on the two surfaces of the dielectric substrates 11, 21 of the high-pass, steep-cutoff, wide-incident-angle frequency selective structure provided in this embodiment have serpentine grooves, and the serpentine grooves are bent twice. The line width of the lateral conductive metal structure of the C-shaped conductive geometric structures 1A3, 1B3, 2A3, 2B3 is 0.2 mm, the line width of the wider longitudinal conductive metal structure on both sides of the C-shaped conductive geometric structures 1A3, 1B3, 2A3, 2B3 is 1.0 mm, and the width of the serpentine grooves on the wider longitudinal conductive metal structures on both sides of the C-shaped conductive geometric structures 1A3, 1B3, 2A3, 2B3 is 0.2 mm.

The zigzag spiral conductive geometric structures 1A2, 1B2, 2A2, 2B2 on the two surfaces of the dielectric substrate 11, 21 of the high-pass, steep-cutoff, wide-incident-angle frequency selective structure provided in this embodiment are connected at the center of the spiral through conductive metal vias 14, 24, and conductive metal arms are extended from the outermost sides of the zigzag spiral conductive geometric structures 1A2, 1B2, 2A2, 2B2 to the edge of the period, and are connected to the conductive metal arms extending from the zigzag spiral conductive geometric structures 1A2, 1B2, 2A2, 2B2 of the adjacent period through conductive metal vias 15, 25 at the edge of the period. The diameter of the conductive metal vias 14, 15, 24, 25 is 0.2 mm.

The C-shaped conductive geometric structures 1A3, 1B3, 2A3, and 2B3 on the two surfaces of the dielectric substrates 11 and 21 of the high-pass, steep-cutoff, wide-incident-angle frequency selective structure provided in this embodiment have opposite opening directions, and the two are connected at the four corners by conductive metal vias 16, 17, 18, 19, 26, 27, 28, and 29, and the diameter of the conductive metal vias 16, 17, 18, 19, 26, 27, 28, and 29 is 0.2 mm.

The spacing between multiple first selection components 10 and multiple second selection components 20 of the high-pass, steep-cutoff, wide-incident-angle frequency selection structure provided in this embodiment is 4 mm, and the strip-shaped through-slots of the first selection components 10 are inserted into the opposite sides of the strip-shaped through-slots of the second selection components 20 to form a mortise and tenon fitting structure, and the first selection components 10 and the second selection components 20 are arranged to be orthogonal and vertically interlaced with each other to form the final embodiment.

The results of the high-pass, steep-cutoff, wide-incident-angle frequency selection structure provided in this embodiment obtained through full-wave simulation software are shown in Figures 6 and 7: This embodiment can achieve the high-pass filtering function of spatial electromagnetic waves below 5 GHz, in any polarization direction, and in a wide incident angle range of 0 to 60 degrees. The relative fractional bandwidth of the passband is as high as 93.3% under the condition of less than 2dB insertion loss, and the transition band between the passband and the stopband is only 0.13GHz under the condition of 13dB suppression, with a steep cutoff effect.

According to one aspect of the present invention, a radome is specifically provided, which includes the high-pass, steep-cutoff, wide-incident-angle frequency selection structure in the above embodiment. The radome can effectively suppress electromagnetic waves in non-working frequency bands, thereby reducing interference outside the working frequency band.

According to another aspect of the present invention, a device for improving isolation between antennas in an antenna system is specifically provided. By setting the device in the antenna system, electromagnetic waves in non-working frequency bands can be effectively suppressed, isolation between antennas in different frequency bands can be improved, and performance of the antenna system can be enhanced.

The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims (10)

1. A wide incidence angle frequency selective structure with high pass and steep cut-off is characterized in that:

Comprises a plurality of rectangular plate-shaped first selection components (10) which are uniformly spaced and parallel to each other and a plurality of rectangular plate-shaped second selection components (20) which are uniformly spaced and parallel to each other, wherein each first selection component (10) and each second selection component (20) are mutually orthogonal and vertically penetrated and arranged; the two side surfaces of each first selection component (10) are divided into a plurality of rectangular first conductive geometric structure printing areas along the length direction of the first selection component, and the same first conductive geometric structures are printed on each first conductive geometric structure printing area; the two side surfaces of each second selection component (20) are divided into a plurality of rectangular second conductive geometric structure printing areas along the length direction of the second selection component, and the same second conductive geometric structures are printed on each second conductive geometric structure printing area; each first conductive geometry printed region is interspersed between two adjacent ones of the second selection elements (20), and each second conductive geometry region is interspersed between two adjacent ones of the first selection elements (10).

2. The high-pass, steep cutoff wide-angle-of-incidence frequency selective structure of claim 1, wherein: the first selection component (10) is a first medium substrate (11) with a plurality of first cutting grooves which are arranged at intervals, the first cutting grooves are strip-shaped through grooves penetrating through the surface of the first medium substrate (11) and are parallel to the width direction of the first medium substrate (11), one first cutting groove is formed in each first conductive geometric structure printing area on the first medium substrate (11), each first cutting groove is positioned between two adjacent first conductive geometric structures, the length direction of each first conductive geometric structure printing area is parallel to the width direction of the first medium substrate (11), each first cutting groove is formed from one short side vertex angle of each first conductive geometric structure printing area to the center of the long side of each first conductive geometric structure printing area, and each first conductive geometric structure on one side of the first medium substrate (11) is overlapped with the first conductive geometric structure on the opposite side after being overturned for half a week along the central axis of the length direction of the first conductive geometric structure printing area where the first conductive geometric structure printing area is positioned;

The second selection component (20) is a second medium substrate (21) with a plurality of second cutting grooves which are arranged at intervals, the second cutting grooves are strip-shaped through grooves penetrating through the surface of the second medium substrate (21) and are parallel to the width direction of the second medium substrate (21), one second cutting groove is formed in each second conductive geometric structure printing area on the second medium substrate (21), each second cutting groove is positioned between two adjacent second conductive geometric structures, the length direction of each second conductive geometric structure printing area is parallel to the width direction of the second medium substrate (21), each second cutting groove is formed from one short side vertex angle of each second conductive geometric structure printing area to the center of the long side of each second conductive geometric structure printing area, and each second conductive geometric structure on one side of the second medium substrate (21) is overlapped with the second conductive geometric structure on the opposite side after being overturned for half a week along the central axis of the length direction of the second conductive geometric structure printing area where the second conductive geometric structure printing area is positioned;

Each first selection component (10) and each second selection component (20) are mutually orthogonal, each first cutting groove on each first selection component (10) is mutually perpendicular and penetrated in sequence with one second cutting groove on each second selection component (20), and each second cutting groove on each second selection component (20) is mutually perpendicular and penetrated in sequence with one first cutting groove on each first selection component (10) when each second selection component (20) and each first selection component (10) are mutually orthogonal.

3. The high-pass, steep cutoff wide-angle-of-incidence frequency selective structure of claim 2, wherein: the first conductive geometric structures comprise spiral conductive geometric structures (1A 2, 1B 2) and C-shaped conductive geometric structures (1A 3, 1B 3), the first conductive geometric structure printing areas on two sides of the first dielectric substrate (11) are opposite to each other, the first spiral conductive geometric structure (1A 2) and the first C-shaped conductive geometric structure (1A 3) are printed on the first conductive geometric structure printing area on one side of the first dielectric substrate (11), and the second spiral conductive geometric structure (1B 2) and the second C-shaped conductive geometric structure (1B 3) are printed on the first conductive geometric structure printing area on the other side of the first dielectric substrate (11);

The C-shaped conductive geometric structures (1A 3, 1B 3) are integrally formed by rectangular sheet-shaped conductive structures with wider two sides and rectangular strip-shaped conductive structures with narrower middle so as to form three sections of right-angle bent C-shaped structures, the width directions of the rectangular sheet-shaped conductive structures on the two sides of the C-shaped conductive geometric structures (1A 3, 1B 3) and the length directions of the rectangular strip-shaped conductive structures in the middle are parallel to the length directions of the printing areas of the first conductive geometric structures, and the rectangular strip-shaped conductive structures are close to the long sides of one side of the printing areas of the first conductive geometric structures and are located at one side far from first cutting grooves in the printing areas of the first conductive geometric structures where the rectangular strip-shaped conductive structures are located; rectangular sheet-shaped conductive structures on two sides of the C-shaped conductive geometric structures (1A 3 and 1B 3) are respectively provided with a right-angle bending snake-shaped slot, openings on two ends of the right-angle bending snake-shaped slot are respectively positioned on a symmetrical axis in the length direction of a printing area of the first conductive geometric structure, four vertex angles of the C-shaped conductive geometric structures (1A 3 and 1B 3) are connected to form a rectangle, conductive metal through holes (16, 17, 18 and 19) penetrating through the plate surface of the first dielectric substrate (11) are sequentially formed, the fifth conductive metal through hole (18) and the sixth conductive metal through hole (19) are positioned between two adjacent first slots, and the C-shaped conductive geometric structures (1A 3 and 1B 3) on two sides of the first dielectric substrate (11) are communicated through the conductive metal through holes (16, 17, 18 and 19);

The spiral conductive geometry (1A 2, 1B 2) is positioned in the middle of the C-shaped conductive geometry (1A 3, 1B 3), one end of the spiral conductive geometry (1A 2, 1B 2) is positioned on the central axis of the length direction of the first cutting groove of the first conductive geometry printing area where the spiral conductive geometry (1A 2, 1B 2) is positioned and is close to the first cutting groove, the other end of the spiral conductive geometry (1A 2, 1B 2) is positioned in the center of the first conductive geometry printing area, one end of the spiral conductive geometry (1A 2, 1B 2) is firstly printed along the width direction of the first conductive geometry printing area and then bent at right angles towards the direction close to the first cutting groove, and then is spirally printed to the other end at right angles, conductive metal through holes (14, 15) penetrating through the plate surface of the first dielectric substrate (11) are respectively formed in two ends of the spiral conductive geometric structures (1A 2, 1B 2), the first conductive metal through holes (14) are located in the center of a printing area of the first conductive geometric structure, the spiral conductive geometric structures (1A 2, 1B 2) on two side surfaces of the first dielectric substrate (11) are communicated through the first conductive metal through holes (14), the second conductive metal through holes (15) are close to the first cutting groove, and the first spiral conductive geometric structure (1A 2) on one side surface of the first dielectric substrate (11) and one second spiral conductive geometric structure (1B 2) which is not right opposite to but adjacent to the first spiral conductive geometric structure on the other side surface of the first dielectric substrate (11) are communicated through the second conductive metal through holes (15).

4. The high-pass, steep cutoff wide-angle-of-incidence frequency selective structure of claim 2, wherein: the second conductive geometric structures comprise spiral conductive geometric structures (2A 2, 2B 2) and C-shaped conductive geometric structures (2A 3, 2B 3), second conductive geometric structure printing areas on two sides of the second medium substrate (21) are opposite to each other, third spiral conductive geometric structures (2A 2) and third C-shaped conductive geometric structures (2A 3) are printed on the second conductive geometric structure printing areas on one side of the second medium substrate (21), and fourth spiral conductive geometric structures (2B 2) and fourth C-shaped conductive geometric structures (2B 3) are printed on the second conductive geometric structure printing areas on the other side of the second medium substrate (21);

The C-shaped conductive geometric structures (2A 3, 2B 3) are integrally formed by rectangular sheet-shaped conductive structures with wider two sides and rectangular strip-shaped conductive structures with narrower middle so as to form three sections of right-angle bent C-shaped structures, the width directions of the rectangular sheet-shaped conductive structures on the two sides of the C-shaped conductive geometric structures (2A 3, 2B 3) and the length directions of the rectangular strip-shaped conductive structures in the middle are parallel to the length directions of the printing areas of the second conductive geometric structures, and the rectangular strip-shaped conductive structures are close to the long sides of one side of the printing areas of the second conductive geometric structures and are positioned at one side far from the second cutting grooves in the printing areas of the second conductive geometric structures where the rectangular strip-shaped conductive structures are positioned; rectangular sheet-shaped conductive structures on two sides of the C-shaped conductive geometric structures (2A 3, 2B 3) are respectively provided with a right-angle bending snake-shaped slot, openings on two ends of the right-angle bending snake-shaped slot are respectively positioned on symmetrical axes in the length direction of a printing area of the second conductive geometric structure, four vertex angles of the C-shaped conductive geometric structures (2A 3, 2B 3) are connected to form a rectangle, conductive metal through holes (26, 27, 28, 29) penetrating through the plate surface of the second dielectric substrate (21) are sequentially formed, a ninth conductive metal through hole (26) and a tenth conductive metal through hole (27) are positioned between two adjacent second slots, and the C-shaped conductive geometric structures (2A 3, 2B 3) on two sides of the second dielectric substrate (21) are communicated through the conductive metal through holes (26, 27, 28, 29);

The other ends of the back-shaped spiral conducting geometric structures (2A 2, 2B 2) are positioned in the center of the second conducting geometric structure printing area, one ends of the back-shaped spiral conducting geometric structures (2A 2, 2B 2) are firstly printed along the width direction of the second conducting geometric structure printing area and then bent at right angles towards the direction close to the second cutting groove, then the back-shaped spiral conducting geometric structures are printed to the other ends in a right-angle spiral mode, two ends of the back-shaped spiral conducting geometric structures (2A 2, 2B 2) are respectively provided with conducting metal through holes (24, 25) penetrating through the plate surface of the second medium substrate (21), the seventh conducting metal through holes (24) are positioned in the center of the second conducting geometric structure printing area, one ends of the back-shaped spiral conducting geometric structures (2A 2, 2B 2) on two sides of the second medium substrate (21) are directly opposite to each other through the second conducting metal through holes (24, 25) of the back-shaped spiral conducting geometric structures (2A 2, 2B 2) on two sides of the second medium substrate (21) are not directly opposite to each other, and the second conducting metal through holes (25) on the second medium substrate (2) are directly opposite to each other, and the back-shaped spiral conducting geometric structures (2B 2) are directly opposite to each other.

5. The high-pass, steep cutoff wide-angle-of-incidence frequency selective structure according to any of claims 3 or 4, wherein: when the first cutting groove of the first dielectric substrate (11) and the second cutting groove of the second dielectric substrate (21) are mutually inserted, the second conductive metal through hole (15) on the first dielectric substrate (11) and the eighth conductive metal through hole (25) on the second dielectric substrate (21) are respectively positioned at two sides of the center point of the width sides of the dielectric substrates (11, 21).

6. The high-pass, steep cutoff wide-angle-of-incidence frequency selective structure according to any of claims 3 or 4, wherein: the lengths of the first cutting groove of the first medium substrate (11) and the second cutting groove of the second medium substrate (21) are 1/2 of the total width of the medium substrates (11 and 21), and the widths of the first cutting groove and the second cutting groove are wider than the thicknesses of the medium substrates (11 and 21).

7. The high-pass, steep cutoff wide-angle-of-incidence frequency selective structure according to any of claims 3 or 4, wherein: the spiral turns of the spiral conductive geometry (1A 2, 1B2, 2A2 and 2B 2) are 1.25-1.5.

8. The high-pass, steep cutoff wide-angle-of-incidence frequency selective structure according to any of claims 3 or 4, wherein: the number of times of bending of the snakelike slotting of the C-shaped conductive geometric structures (1A 3, 1B3, 2A3 and 2B 3) is 2.

9. Use of a high-pass, steep cutoff wide-angle-of-incidence frequency selective structure according to any of claims 1-8, characterized in that: the high-pass steep-cut wide-angle-of-incidence frequency selective structure is applied to radomes.

10. Use of a high-pass, steep cutoff wide-angle-of-incidence frequency selective structure according to any of claims 1-8, characterized in that: the high-pass and steep-cut wide-angle-of-incidence frequency selection structure is applied to a device for improving the isolation between antennas in an antenna system.