CN108232397A - Miniaturized merit divides ware - Google Patents

Abstract

The present invention relates to the field of electronic devices, in particular to a miniaturized power splitter, which includes two power branches, a microstrip connection unit, a dielectric plate and a number of metal conductive vias, any of which includes a microstrip connection A going circuit and a reverse circuit connected to the unit, the going circuit includes a going microstrip-coplanar waveguide transmission unit connected end to end in sequence, and the reverse circuit includes a reverse microstrip coplanar waveguide transmission unit connected end to end, and the going microstrip ‑The coplanar waveguide transmission unit includes a microstrip transmission line segment at the top of the dielectric plate and a coplanar waveguide transmission line segment at the bottom of the dielectric plate connected end to end through metal conductive vias, and the reverse microstrip‑coplanar waveguide transmission unit The microstrip transmission line segment at the top of the dielectric plate and the coplanar waveguide transmission line segment at the bottom of the dielectric plate connected end to end through the hole, the present invention adopts the double-layer microstrip-coplanar waveguide Z-shaped cross-folding transmission line to realize the power splitter miniaturization.

Description

A miniaturized power divider

technical field

The invention relates to the field of electronic devices, in particular to a miniaturized power divider.

Background technique

With the increasing demand for miniaturization of microwave systems and equipment, the miniaturization of radio frequency devices has attracted more and more attention, and the miniaturization of the transmission line that constitutes the main structure of radio frequency devices is a key factor in determining the size of radio frequency devices.

The power splitter (also called power divider) is used in the radio frequency link to meet special functional requirements (such as the feed network of large array antennas) to divide one radio frequency signal into two or more outputs with equal or unequal energy The radio frequency device can also combine two or more signal energies into one output, which is also called a combiner at this time.

The power divider is one of the indispensable devices in various modern wireless communication systems. It is widely used in various microwave radio frequency circuits, such as power combining network, frequency multiplier, mixer and array antenna and so on. The power splitter with planar structure is the most widely used due to its advantages of small size, low cost, and easy integration. With the continuous development of modern high-efficiency communication technology, higher requirements are put forward for power splitters. The basic requirements are: small size, low insertion loss, consistent output amplitude and phase, good isolation between ports, wide frequency band, simple circuit form, etc.

The power splitter can be divided into microstrip type and cavity type in terms of structure. The microstrip type uses a quarter-wavelength microstrip line, and the cavity type uses a resonant cavity. Microstrip power splitters are widely used in radio frequency circuits due to their low profile, easy integration, and low cost. However, due to the limitation of 1/4 wavelength transmission lines, microstrip power splitters are not easy to achieve miniaturized design. Some of the miniaturized power splitter structures based on serpentine or multi-layer transmission line structures have too many layers of circuit boards, complex structures, and high costs, while others are not highly integrated and are susceptible to environmental interference. For example, the authorized Chinese invention patent CN201410302256.8 discloses a miniaturized microstrip power splitter, which reduces the volume of the power splitter by arranging the microstrip transmission line in a multi-layer circuit board, but because the three-layer The structure of the circuit board is expensive and complex, and all transmission lines are microstrip transmission lines, which generate large radiation interference and are easily interfered by the surrounding environment, which greatly limits the performance of the power splitter.

It is difficult for current technologies to meet the requirements of low cost, high performance and miniaturization at the same time.

Contents of the invention

According to the shortcomings of the prior art above, the present invention provides a miniaturized power splitter with small volume, simple circuit form, strong anti-interference ability and low cost.

The technical solution adopted in the technical problem solved by the present invention is as follows: including two power branch nodes, one input transmission line, two microstrip connection units, two output ports, metal floor, dielectric plate and several metal conductive vias, the metal Conductive vias run through the upper and lower surfaces of the dielectric board, the metal floor is arranged on the lower surface of the dielectric board, the two power branch structures are symmetrically arranged left and right, and any of the work branches includes a forward circuit and a reverse circuit , the output end of the outgoing circuit is electrically connected to the input end of the reverse circuit through a microstrip connection unit, the input ends of the outgoing circuits of the two power branch nodes are commonly connected to the input transmission line, and the two power branch nodes The output ends of the reverse circuit are respectively connected to different output ports, and the outgoing circuit includes several outgoing microstrip-coplanar waveguide units arranged from front to back along the dielectric board, and the head and the tail are sequentially connected through metal conductive vias. The microstrip-coplanar waveguide unit includes a "Z"-shaped coplanar waveguide transmission line section A arranged on the lower surface of the dielectric board and a "Z"-shaped microstrip transmission line section A arranged on the upper surface of the dielectric board. The coplanar waveguide transmission line section A is connected to the end of the microstrip transmission line segment A through metal conductive vias. The reverse circuit includes several reverse microstrip-coplanar waveguides arranged from the back to the front along the dielectric plate and connected from the end to the end through metal conductive vias. unit, the reverse microstrip-coplanar waveguide unit includes a "Z"-shaped coplanar waveguide transmission line segment B arranged on the lower surface of the dielectric board and a "Z"-shaped microstrip transmission line segment B arranged on the upper surface of the dielectric board, The head and tail of the coplanar waveguide transmission line section B and the microstrip transmission line section B are connected through metal conductive vias, the coplanar waveguide transmission line section A and the coplanar waveguide transmission line section B are arranged at intervals, the microstrip transmission line section A and the microstrip transmission line section The transmission line segments B are arranged at intervals.

The microstrip transmission line is a type of microwave transmission line developed along with people's increasing requirements for miniaturization of microwave systems and equipment. It has the advantages of small size, light weight, wide frequency band, and can be integrated, and is widely used in microwave miniaturization systems; coplanar waveguide transmission line is a transmission line arranged on one side of a dielectric plate, and a specific distance within the same plane of the transmission line A large metal floor is arranged so that the transmission line is located inside the groove of the slotted metal floor. Because both sides of the coplanar waveguide transmission line are surrounded by metal grounds, the edge effect of the transmission line is effectively suppressed. Due to the isolation of the metal ground between the double transmission lines, the coupling can basically be ignored. In addition, the coplanar waveguide transmission line also has the characteristics of high transmission frequency and easy processing, and is widely used in microwave systems.

The transmission line used in the present invention sets the coplanar waveguide transmission line in the metal ground of the microstrip line, and adopts a Z-shaped cross-folding structure, combining the advantages of the two types of lines and their physical structure characteristics to form a double-layer microstrip-common The surface waveguide Z-shaped cross-folding transmission line places a longer transmission line in a specific physical space, and uses such a transmission line to design a power splitter, which efficiently realizes the miniaturization of the power splitter.

Among them, the preferred way is:

The head end of the going microstrip-coplanar waveguide unit is one end of the coplanar waveguide transmission line section A, and the other end of the coplanar waveguide transmission line section A is connected to one end of the microstrip transmission line section A through a metal conductive via hole, so The other end of the microstrip transmission line section A is used as the tail end of the going microstrip-coplanar waveguide unit; the head end of the reverse microstrip-coplanar waveguide unit is an end of the coplanar waveguide transmission line section B, and the coplanar The other end of the waveguide transmission line segment B is connected to one end of the microstrip transmission line segment B through a metal conductive via, and the other end of the microstrip transmission line segment B is used as the tail end of the reverse microstrip-coplanar waveguide unit; the outgoing circuit The input end of the circuit is the head end of the microstrip-coplanar waveguide unit, and the output end of the circuit is set to the tail end of the microstrip-coplanar waveguide unit; the input terminal of the reverse circuit is a reverse microstrip - the head end of the coplanar waveguide unit, the output end of the reverse circuit is set as the reverse microstrip-the tail end of the coplanar waveguide unit.

The microstrip connection unit includes metal conductive vias and an "L"-shaped microstrip transmission line segment C arranged on the upper surface of the dielectric board. One end of the microstrip transmission line segment C is connected to the output end of the outgoing circuit, and the other end is connected to the The conductive via hole is connected with the input end of the reverse circuit.

The signal trend on the two power branch nodes of the present invention is all the same, specifically:

An input transmission line is set on the top of the dielectric board and is connected to the input end of the outgoing circuit of the two power branches. On one end of two different coplanar waveguide transmission line segments A at the bottom of the dielectric board, the input signal is transmitted from the input transmission line through the metal conductive via to one end of the coplanar waveguide transmission line segment A, and then from the coplanar waveguide transmission line segment A The other end is transmitted to the next metal conductive via, through which the metal conductive via is transmitted upward to the microstrip transmission line segment A arranged on the top of the dielectric plate, so that the signal is transmitted on a going microstrip-coplanar waveguide unit, The output from the other end of the microstrip transmission line segment A of the going microstrip-coplanar waveguide unit enters the next going microstrip-coplanar waveguide unit through the metal conductive via hole.

The microstrip connection unit of the "L" shape, i.e. the microstrip transmission line segment C, has two mutually perpendicular arms, and one end of the microstrip transmission line segment C is coplanar with the output end of the going circuit (that is, the going microstrip-coplanar The end of the microstrip transmission line section A in the waveguide unit) is connected, and the other end is connected downward to the input end of the reverse circuit through a metal conductive via (that is, the coplanar waveguide transmission line section of the reverse microstrip-coplanar waveguide unit the head end of B).

The signal enters the input end of the reverse circuit from the output end of the outgoing circuit through the microstrip connection unit and the metal conductive via, and is transmitted along the reverse circuit to the tail end of the last reverse microstrip-coplanar waveguide unit (that is, the last end of a microstrip transmission line segment B), and output from the output port.

An isolation resistor is set between the output ends of the reverse circuits of the two power branches.

Both ends of the isolation resistor are respectively electrically connected between the last microstrip transmission line segment B in the reverse circuit of the two power branches, which can effectively improve the signal isolation of the two output ports.

The metal conductive vias are perpendicular to the upper and lower surfaces of the dielectric board.

The "Z" shape structure of the coplanar waveguide transmission line segment A, the "Z" shape structure of the coplanar waveguide transmission line segment B, the "Z" shape structure of the microstrip transmission line segment A, and the "Z" shape of the microstrip transmission line segment B The structure includes a middle end and two ends, each "Z"-shaped end is perpendicular to the middle end and extends in opposite directions from the two ends of the middle end, and each "Z"-shaped two ends The distance between them is equal.

The middle part of the microstrip transmission line section A and the middle part of the coplanar waveguide transmission line section B directly below it coincide with the center in the normal direction of the dielectric plate, and the middle part of the microstrip transmission line section B and the middle part of the coplanar waveguide transmission line section B directly below it coincide. The center of the coplanar waveguide transmission line section A coincides with the center in the normal direction of the dielectric plate.

In a single branch node, the shortest distance between two ends in the same "Z"-shaped structure is defined as l, and the metal conductive vias on a single branch node are on the left and right sides of the dielectric board from the front If it is set backwards, the distance between the central axes of the front and rear metal conductive vias on one side is defined as d. Unlike conventional microstrip transmission lines or coplanar waveguide transmission lines, this new double-layer microstrip-coplanar waveguide Z The impedance characteristics of the cross-shaped cross-fold transmission line are related to the length of l and the distance d. By adjusting l and d, the impedance and phase of the new double-layer microstrip-coplanar waveguide Z-shaped cross-folded transmission line can be controlled.

The dielectric plate is made of FR-4 material, with a thickness of 0.5 mm, a relative permittivity of 4.4, and a loss tangent of 0.02. The microstrip transmission line section A, microstrip transmission line section B, and coplanar waveguide transmission line section A , Coplanar waveguide transmission line section B is made of metal copper material, its thickness is 0.02mm, impedance is 70.7Ω+j*0Ω, and the diameter of the metal via hole is 0.3mm.

The present invention has the following beneficial effects: (1) the transmission line in the power splitter of the present invention application is a microstrip line and a coplanar waveguide transmission line respectively arranged on both sides of a layer of dielectric board, because the microstrip transmission line medium corresponds to the plane and the coplanar waveguide The waveguide transmission line medium has no transmission line, so the coplanar microstrip transmission line is arranged in the complete floor of the non-coplanar microstrip transmission line structure, which makes full use of the space of the corresponding surface of the microstrip transmission line and the coplanar waveguide transmission line medium, which is better than the multilayer in the prior art. The structure of the circuit board is simpler, effectively reduces the cost, and longer transmission lines can be placed in the specific physical space in the power splitter, and is more conducive to the realization of miniaturization; (2) the small power splitter of the present invention The transmission line is a structural form in which a coplanar waveguide transmission line is arranged in the metal floor of the microstrip transmission line. While realizing the transmission of high-frequency signals, it can effectively suppress the electromagnetic radiation of the microstrip transmission line, has stronger anti-interference performance, and effectively improves the performance. The ability of the splitter to transmit high-frequency signals.

Description of drawings

Fig. 1 is a schematic diagram of the upper surface structure of the present invention;

Fig. 2 is a schematic diagram of the lower surface structure of the present invention;

Fig. 3 is a three-dimensional structural schematic diagram of a branch node of the present invention;

Fig. 4 is a schematic diagram of the phase characteristics of the transmission line at different d in a single power branch in the present invention;

Fig. 5 is a schematic diagram of the impedance characteristics of the transmission line at different d times in a single power branch in the present invention;

Fig. 6 is a schematic diagram of the phase characteristics of the transmission line at different l times in a single power branch in the present invention;

Fig. 7 is a schematic diagram of the impedance characteristics of the transmission line at different l times in a single power branch in the present invention;

Fig. 8 is a schematic diagram of simulation and test comparison of input return loss and output port power division ratio parameters of the miniaturized power splitter according to Embodiment 1 of the present invention;

9 is a schematic diagram of the simulation and test comparison of the output port return loss and isolation parameters of the miniaturized power splitter according to Embodiment 1 of the present invention;

Fig. 10 is a schematic diagram of the simulation and test comparison of the phase parameters of the miniaturized power splitter according to Embodiment 1 of the present invention;

11 is a schematic diagram of a three-dimensional structure of a double-layer microstrip-coplanar waveguide transmission line;

Fig. 12 is the schematic diagram of the influence of the variation of parameter L ₀ on this transmission line impedance characteristic in double-layer microstrip-coplanar waveguide transmission line structure;

Fig. 13 is the schematic diagram of the influence of the change of parameter w ₁ on the impedance characteristic of this transmission line in the double-layer microstrip-coplanar waveguide transmission line structure;

Fig. 14 is the schematic diagram of the impact of the change of parameter g on the impedance characteristic of this transmission line in the double-layer microstrip-coplanar waveguide transmission line structure;

In the figure: 1. Input transmission line 100, microstrip transmission line D 101, coplanar waveguide transmission line D 2, microstrip transmission line segment C3, output port 4, metal floor 5, dielectric plate 6, metal conductive via 71, coplanar waveguide transmission line Section A 72, microstrip transmission line section A 81, coplanar waveguide transmission line section B 82, microstrip transmission line section B 9, isolation resistor.

Detailed ways

The present invention will be further described below in conjunction with the accompanying drawings.

Example 1:

In order to make the object, technical solution and advantages of the present invention clearer, the present invention will be described in further detail below with reference to the accompanying drawings and preferred embodiments. However, it should be noted that many of the details listed in the specification are only for readers to have a thorough understanding of one or more aspects of the present invention, and these aspects of the present invention can be implemented even without these specific details.

As shown in Figures 1 to 14, a miniaturized power splitter according to the present invention includes two power branch nodes, an input transmission line 1, two microstrip connection units, two output ports 3, and a metal floor 4 , a dielectric plate 5 and a number of metal conductive vias 6, the metal conductive vias 6 run through the upper and lower surfaces of the dielectric plate 5, the metal floor 4 is arranged on the lower surface of the dielectric plate 5, and the two power branch structures are left and right Symmetrically arranged, any one of the power branches includes a going circuit and a reverse circuit, the output end of the going circuit is electrically connected to the input end of the reverse circuit through a microstrip connection unit, and the two power branches The input end of the outgoing circuit is commonly connected to the input transmission line 1, and the output ends of the reverse circuits of the two power branches are respectively connected to different output ports 3, and the outgoing circuit includes several , the outgoing microstrip-coplanar waveguide unit connected in turn through the metal conductive via 6, and the outgoing microstrip-coplanar waveguide unit includes a "Z"-shaped coplanar waveguide transmission line segment A71 arranged on the lower surface of the dielectric board 5 and The "Z" shaped microstrip transmission line section A72 arranged on the upper surface of the dielectric board 5, the end of the coplanar waveguide transmission line section A71 and the microstrip transmission line section A72 are connected through metal conductive vias 6, and the reverse circuit includes several The reverse microstrip-coplanar waveguide units arranged from the back to the front along the dielectric plate 5 and connected in turn through the metal conductive vias 6, the reverse microstrip-coplanar waveguide units include the bottom surface of the dielectric plate 5 The "Z" shaped coplanar waveguide transmission line section B81 and the "Z" shaped microstrip transmission line section B82 arranged on the upper surface of the dielectric board 5, the head and tail of the coplanar waveguide transmission line section B81 and the microstrip transmission line section B82 pass through a metal conductive pass The holes 6 are connected, the coplanar waveguide transmission line section A71 and the coplanar waveguide transmission line section B81 are arranged at intervals, and the microstrip transmission line section A72 and the microstrip transmission line section B82 are arranged at intervals.

The microstrip transmission line is a type of microwave transmission line developed along with people's increasing requirements for miniaturization of microwave systems and equipment. It has the advantages of small size, light weight, wide frequency band, and can be integrated, and is widely used in microwave miniaturization systems; coplanar waveguide transmission line is a transmission line arranged on one side of a dielectric plate, and a specific distance within the same plane of the transmission line A large metal floor is arranged so that the transmission line is located inside the groove of the slotted metal floor. Because both sides of the coplanar waveguide transmission line are surrounded by metal grounds, the edge effect of the transmission line is effectively suppressed. Due to the isolation of the metal ground between the double transmission lines, the coupling can basically be ignored. In addition, the coplanar waveguide transmission line also has the characteristics of high transmission frequency and easy processing, and is widely used in microwave systems.

The basic structural form of the transmission line adopted in the present invention is a novel double-layer microstrip-coplanar waveguide transmission structure in which a coplanar waveguide transmission line is arranged in the complete metal floor of the microstrip transmission line. This structure, while realizing the transmission of high-frequency signals, The electromagnetic radiation of the non-coplanar transmission line can be effectively suppressed, and the purpose that both transmission lines can transmit electromagnetic signals can be finally realized.

As shown in Figure 11, the microstrip transmission line D100 is arranged on the top of the dielectric plate 5 along the front-to-back direction, and its rear end is connected downwards to the rear end of the coplanar waveguide transmission line D101 through the metal conductive via 6, and the coplanar waveguide transmission line D101 It is arranged at the bottom of the dielectric plate 5 and directly below the microstrip transmission line D100 along the front-rear direction. After several experiments, it is concluded that the impedance characteristics of the new double-layer microstrip-coplanar waveguide transmission line are mainly affected by the unidirectional length L ₀ , the width w ₁ of the microstrip transmission line D100, and the distance between the transmission line and the metal groove of the coplanar waveguide transmission line. In the design process, when the user adjusts the required impedance, the real part of the double-layer microstrip-coplanar waveguide transmission line can be precisely adjusted by changing parameters such as L ₀ , w ₁ and g and the imaginary impedance.

It can be seen from Figure 12 that, unlike traditional microstrip and coplanar waveguide transmission lines, the impedance of the new double-layer microstrip-coplanar waveguide transmission line will also change significantly with frequency. When the phase shift is less than -90°, as the frequency increases, the real part of the transmission line impedance and the inductance gradually increase. When the phase shift is greater than -90°, as the frequency increases, the real part of the transmission line impedance decreases and the capacitance increases. But for different L ₀ , the magnitude of the real part and the imaginary part of the double-layer microstrip-coplanar waveguide transmission line will not change greatly. It is worth noting that when the imaginary part impedance of the transmission line is zero, the real part resistance is close to or reaches the maximum value, and the phase shift is 0.83λ/2 at this time. This is due to the common influence of the microstrip transmission line, the coplanar waveguide transmission line and the alternating coupling of the two.

As an important part of the double-layer microstrip-coplanar waveguide transmission line structure, the line width w ₁ of the microstrip transmission line D100 and the gap width g between the transmission line and the metal groove of the coplanar waveguide transmission line D101 are important factors affecting the transmission impedance characteristics of the structure. parameter. Since the influence of changes in w ₁ and g on the transmission phase can be basically ignored, Fig. 13 to Fig. 14 only show the change curves of the impedance of the double-layer microstrip-coplanar waveguide transmission line with frequency when w ₁ and g are different. It can be seen _from the figure that as w ₁ or g becomes larger, the real part of the impedance of the double-layer microstrip-coplanar waveguide transmission line will increase. The part gradually changes from inductive to capacitive, because the smaller _w1 or g will introduce stronger capacitive coupling, so that the capacitive in the overall equivalent link will become larger.

In the present invention, each microstrip transmission line and coplanar waveguide transmission line of the double-layer microstrip-coplanar waveguide transmission line are arranged in a "Z" shape, and their ends are connected through metal conductive vias 6, and are set as cross-folding laying The going circuit and the reverse circuit constitute a double-layer microstrip-coplanar waveguide Z-shaped cross-folding transmission line, which combines the advantages and physical structure characteristics of the microstrip line and the coplanar waveguide transmission line, and places a longer transmission line in a specific physical space , the transmission line is used to design a power splitter, and the miniaturization of the power splitter is realized efficiently.

The head end of the going microstrip-coplanar waveguide unit is one end of the coplanar waveguide transmission line section A71, and the other end of the coplanar waveguide transmission line section A71 is connected to one end of the microstrip transmission line section A72 through the metal conductive via 6, The other end of the microstrip transmission line section A72 is used as the tail end of the going microstrip-coplanar waveguide unit; the head end of the reverse microstrip-coplanar waveguide unit is an end of the coplanar waveguide transmission line section B81, and the common The other end of the planar waveguide transmission line section B81 is connected to one end of the microstrip transmission line section B82 through the metal conductive via 6, and the other end of the microstrip transmission line section B82 is used as the tail end of the reverse microstrip-coplanar waveguide unit; The input end of the going circuit is the head end of the going microstrip-coplanar waveguide unit, and the output end of the going circuit is set to the tail end of the going microstrip-coplanar waveguide unit; the input end of the reverse circuit is reverse The head end of the microstrip-coplanar waveguide unit, the output end of the reverse circuit is set as the tail end of the reverse microstrip-coplanar waveguide unit.

The microstrip connection unit includes a metal conductive via 6 and an "L"-shaped microstrip transmission line segment C2 arranged on the upper surface of the dielectric board 5. One end of the microstrip transmission line segment C2 is connected to the output end of the outgoing circuit, and the other end is connected to the output end of the outgoing circuit. It is connected to the input end of the reverse circuit through the metal conduction via hole 6 .

The direction of signals on the two power branch nodes in this embodiment is the same, specifically:

An input transmission line 1 is set on the top of the dielectric board 5 and connected to the input ends of the outgoing circuits of the two power branches, that is, the input transmission line 1 is respectively connected downwards to the two power branches at the bottom of the dielectric board 5 through two metal conductive vias 6 . On one end of a different coplanar waveguide transmission line section A71, the signal is transmitted from the other end of the coplanar waveguide transmission line section A71 to the next metal conductive via hole 6, and is transmitted upwards to the dielectric plate 5 through the metal conductive via hole 6. On the microstrip transmission line segment A72 at the top, so that the signal completes the transmission on a going microstrip-coplanar waveguide unit, and then passes through the output from the other end of the microstrip transmission line section A72 going to the microstrip-coplanar waveguide unit The metal conduction via hole 6 enters the next destination microstrip-coplanar waveguide unit.

The microstrip connection unit of the "L" shape, that is, the microstrip transmission line segment C2, has two mutually perpendicular arms, and one end of the microstrip transmission line segment C2 is connected to the output end of the outgoing circuit (that is, the outgoing microstrip-coplanar waveguide The tail end of the microstrip transmission line section A72 in the unit) is connected, and the other end is connected downwards to the input end of the reverse circuit through the metal conductive via 6 (that is, the coplanar waveguide transmission line section of the reverse microstrip-coplanar waveguide unit head end of B81).

The signal enters the input end of the reverse circuit after passing through the microstrip connection unit and the metal conductive via 6 from the output end of the outgoing circuit, and is transmitted along the reverse circuit to the tail end of the last reverse microstrip-coplanar waveguide unit (that is, end of the last microstrip transmission line segment B82), and then output from output port 3.

An isolation resistor 9 is arranged between the output ends of the reverse circuits of the two power branches.

Both ends of the isolation resistor 9 are respectively electrically connected between the last microstrip transmission line segment B82 in the reverse circuit of the two power branches, which effectively improves the signal isolation of the two output ports in this embodiment.

The metal conductive vias 6 are perpendicular to the upper and lower surfaces of the dielectric board 5 .

The "Z" shape structure of the coplanar waveguide transmission line section A71, the "Z" shape structure of the coplanar waveguide transmission line section B81, the "Z" shape structure of the microstrip transmission line section A72, and the "Z" shape of the microstrip transmission line section B82 The structure includes a middle end and two ends, each "Z"-shaped end is perpendicular to the middle end and extends in opposite directions from the two ends of the middle end, and each "Z"-shaped two ends The distance between them is equal.

The middle part of the microstrip transmission line segment A72 and the middle part of the coplanar waveguide transmission line segment B81 directly below it coincide with the center in the normal direction of the dielectric plate 5, and the middle part of the microstrip transmission line segment B82 and The center of the coplanar waveguide transmission line segment A71 coincides with the center of the dielectric plate 5 in the normal direction.

In a single branch node, the shortest distance between two ends in the same "Z" shaped structure is defined as l, and the metal conductive via hole 6 on the single branch node is on the dielectric board 5 at the left and right sides The side is set from front to back, and the distance between the central axes of the front and rear metal conductive vias 6 on one side is defined as d. Unlike conventional microstrip transmission lines or coplanar waveguide transmission lines, this new double-layer microstrip-common The impedance characteristics of the surface waveguide Z-shaped cross-folded transmission line are related to the length of l and the distance d. By adjusting l and d, the impedance and phase of the new double-layer microstrip-coplanar waveguide Z-shaped cross-folded transmission line can be controlled. Fig. 4～Fig. 7 has demonstrated the influence of these two parameters on the phase characteristics and the impedance characteristic of this novel double-layer microstrip-coplanar waveguide Z-shaped crossing backfold transmission line, and wherein, Fig. 4 is the single power branch in the present invention The phase characteristic figure of transmission line when different d, Fig. 5 is the impedance characteristic figure of transmission line of single power branch in the time of different d among the present invention, Fig. 6 is the phase characteristic figure of transmission line of single power branch in different l time among the present invention, Fig. 7 is the impedance characteristic diagram of the transmission line of a single power branch in different l times in the present invention.

It can be seen that with the increase of d and l, the actual length of the double-layer microstrip-coplanar waveguide Z-shaped cross-fold back-fold transmission line becomes longer, and the phase shift speed becomes faster. But for the impedance, the frequency point near the phase shift -90° is still the inflection point of the periodic change of the impedance of the structure. In the frequency range where the phase shift is less than -90°, as d increases, the introduced top microstrip transmission line structure and the bottom coplanar waveguide transmission line structure are also longer, and the impedance variation range of the structure will also be slightly smaller. On the other hand, for the reactance, the increase of d introduces a longer top-layer microstrip transmission line structure and a bottom coplanar waveguide transmission line, and also adds stronger capacitive characteristics, which is comparable to the non-intersected double-layer microstrip-coplanar waveguide The Z-type transmission line is different. As l increases, the change amplitude of the real part and imaginary part of the structure impedance of the double-layer microstrip-coplanar waveguide Z-type cross-folded transmission line will also increase.

The dielectric plate 5 is made of FR-4 material, with a thickness of 0.5 mm, a relative permittivity of 4.4, and a loss tangent of 0.02. The microstrip transmission line section A72, microstrip transmission line section B82, and coplanar waveguide transmission line section Both A71 and the coplanar waveguide transmission line section B81 are made of metal copper, with a thickness of 0.02mm and an impedance of 70.7Ω+j*0Ω, and the diameter of the metal via 6 is 0.3mm.

In this embodiment, the overall size of the small power divider is designed to be 11mm*8mm, preferably, d=1mm, w ₀ =0.95mm, w ₁ =0.5mm, w ₂ =0.3mm, g=0.1mm, l=3.5 , as shown in Figure 2, d is the distance between the centers of two metal conductive vias 6 on the same side in a single power branch node, w ₀ is the Z-shaped structure of the microstrip transmission line segment B82 connected to the output port 3 The width of the middle end, w ₁ is the width of the middle end of the "Z" shape structure of the microstrip transmission line segment A72 and the microstrip transmission line segment B82 not connected to the output port 3, and w ₂ is the coplanar waveguide transmission line segment A71 and the coplanar waveguide The width of the transmission line inside the metal slot of the transmission line section B81, g is the width of the gap between the transmission line of the coplanar waveguide transmission line section A71 and the coplanar waveguide transmission line section B81 and the transmission line to the metal slot, and l is the width of each "Z"-shaped structure The shortest distance between the center axes of two ends. The simulation and test results of the functional parameters of the miniaturized power divider of this embodiment are shown in Figure 8, Figure 9 and Figure 10. Compared with the traditional microstrip power divider, under the premise that the performance is basically unchanged, this embodiment The size of the power divider is reduced by 88%. In the figure, S ₁₁ is the return loss at the input end, S ₁₂ is the power division ratio from the input end to one of the output ports, and S ₁₃ is the power division ratio from the input end to the other output port , S ₂₂ is the return loss of one output port, S ₃₃ is the return loss of the other output port, and S ₂₃ is the isolation between the signals of the two output ports. The simulation results show that when the center frequency is 1GHz, the power division Port power division ratios are S ₁₂ ＝-3.14dB and S ₁₃ ＝-3.11dB, S ₁₁ ＝-48.65dB, S ₂₂ ＝-25.83dB, S ₃₃ ＝-25.98dB, power division port isolation S ₂₃ ＝- 28.76dB. This shows that the power division loss of the power divider is less than 5.6% at the working frequency point. However, generally too compact structural design often introduces strong electromagnetic coupling. The 3dB Wilkinson power divider based on this structural design has very small insertion loss at the resonant frequency, which proves that this structure can reduce the overall size of the device while reducing the overall size of the device. It can also meet the requirements of the relevant electromagnetic characteristics of the device. -15dB impedance bandwidth from 0.69GHz to 1.25GHz. On the other hand, the test results show that the -15dB impedance bandwidth reaches 62.8% from 0.73GHz to 1.30GHz. The frequency band where the isolation of the power split port is better than 15dB is 0.43GHz to 1.69GHz. Figure 10 shows the distribution of the phase characteristics of the power divider. The results show that in the range of 0.75GHz to 1.35GHz, the phase difference of the output ports is within 0°±4°. The results show that the power splitter based on the double-layer microstrip-coplanar waveguide Z-shaped cross-fold back-fold transmission line achieves the design goal of miniaturization under the premise of ensuring the performance of the power splitter.

The above are all embodiments of the present invention, and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process conversion made by using the description of the invention and the contents of the accompanying drawings, or directly or indirectly used in other related technical fields , are all included in the scope of patent protection of the present invention in the same way.

Claims (8)

1. A miniaturized power divider is characterized in that: it comprises two power branches, an input transmission line, two microstrip connection units, two output ports, a metal floor, a dielectric plate and some metal conduction vias, so The metal conductive via holes run through the upper and lower surfaces of the dielectric board, the metal floor is arranged on the lower surface of the dielectric board, and the two power branch structures are symmetrically arranged on the left and right. to the circuit, the output end of the outgoing circuit is electrically connected to the input end of the reverse circuit through a microstrip connection unit, the input ends of the outgoing circuits of the two power branches are commonly connected to the input transmission line, and the two power branches The output terminals of the reverse circuit of the branch are respectively connected to different output ports, and the outgoing circuit includes several outgoing microstrip-coplanar waveguide units arranged from front to back along the dielectric board and connected in turn through metal conductive vias. The outgoing microstrip-coplanar waveguide unit includes a "Z" shaped coplanar waveguide transmission line section A arranged on the lower surface of the dielectric plate and a "Z" shaped microstrip transmission line section A arranged on the upper surface of the dielectric plate, and the coplanar waveguide The head and tail of the transmission line section A and the microstrip transmission line section A are connected through metal conductive vias, and the reverse circuit includes several reverse microstrip-common circuits arranged from the back to the front along the dielectric board and connected from the beginning to the end through metal conductive vias. A planar waveguide unit, the reverse microstrip-coplanar waveguide unit includes a "Z"-shaped coplanar waveguide transmission line section B arranged on the lower surface of the dielectric board and a "Z"-shaped microstrip transmission line section arranged on the upper surface of the dielectric board B, the end of the coplanar waveguide transmission line section B and the microstrip transmission line section B are connected through metal conductive vias, the coplanar waveguide transmission line section A and the coplanar waveguide transmission line section B are arranged at intervals, and the microstrip transmission line section A and the microstrip transmission line segment B are arranged at intervals. 2. A miniaturized power splitter according to claim 1, characterized in that: the head end of the outgoing microstrip-coplanar waveguide unit is one end of the coplanar waveguide transmission line section A, and the coplanar waveguide transmission line The other end of the section A is connected to one end of the microstrip transmission line section A through a metal conductive via, and the other end of the microstrip transmission line section A is used as the tail end of the going microstrip-coplanar waveguide unit; the reverse microstrip- The head end of the coplanar waveguide unit is one end of the coplanar waveguide transmission line section B, and the other end of the coplanar waveguide transmission line section B is connected to one end of the microstrip transmission line section B through a metal conductive via, and the microstrip transmission line section B The other end of the reverse microstrip-coplanar waveguide unit is used as the tail end; the input end of the going circuit is the head end of the going microstrip-coplanar waveguide unit, and the output end of the going circuit is set to go to the microstrip-coplanar waveguide unit. The tail end of the coplanar waveguide unit; the input end of the reverse circuit is the head end of the reverse microstrip-coplanar waveguide unit, and the output end of the reverse circuit is set to the reverse microstrip-coplanar waveguide unit tail end. 3. A miniaturized power splitter according to claim 2, characterized in that: the microstrip connection unit includes metal conductive vias and an "L" shaped microstrip transmission line section C arranged on the upper surface of the dielectric board, One end of the microstrip transmission line segment C is connected to the output end of the outgoing circuit, and the other end is connected to the input end of the reverse circuit through a metal conductive via. 4. A miniaturized power divider according to claim 2, characterized in that: an isolation resistor is provided between the output ends of the reverse circuits of the two power branch nodes. 5 . The miniaturized power divider according to claim 4 , wherein the metal conductive vias are perpendicular to the upper and lower surfaces of the dielectric board. 6. A miniaturized power splitter according to any one of claims 1 to 5, characterized in that: the "Z" shape structure of the coplanar waveguide transmission line section A, the "Z" shape structure of the coplanar waveguide transmission line section B, The Z"-shaped structure, the "Z"-shaped structure of the microstrip transmission line segment A, and the "Z"-shaped structure of the microstrip transmission line segment B all include a middle end and two ends, and each "Z"-shaped end is connected to the The middle end is vertical and extends in opposite directions from the two ends of the middle end respectively, and the distance between the two ends of each "Z" shape is equal. 7. A miniaturized power splitter according to claim 6, characterized in that: the middle part of the microstrip transmission line section A and the middle part of the coplanar waveguide transmission line section B directly below it are in the normal direction of the dielectric plate The centers in the direction coincide, and the centers of the middle part of the microstrip transmission line segment B and the middle part of the coplanar waveguide transmission line segment A directly below it coincide in the normal direction of the dielectric plate. 8. A miniaturized power divider according to claim 7, characterized in that: the dielectric plate is made of FR-4 material, with a thickness of 0.5 mm, a relative permittivity of 4.4, and a loss tangent of 0.02 , the microstrip transmission line section A, the microstrip transmission line section B, the coplanar waveguide transmission line section A, and the coplanar waveguide transmission line section B are all made of metallic copper material, with a thickness of 0.02mm and an impedance of 70.7Ω+j*0Ω, The diameter of the metal via hole is 0.3mm.