CN100576632C - Antenna with partially reflecting surface - Google Patents

Abstract

The present invention relates to a partial reflector antenna, and more particularly, to a partial reflector antenna including a reflector plate formed by a microstrip antenna array and having advantages of low side lobes and high gain. It includes: a substrate having an upper surface, a signal input/output port formed on the upper surface for receiving and outputting a high frequency signal; a reflection plate for partially reflecting the high frequency signal; and a plurality of supporting units. The surface of the reflecting plate is provided with a first antenna array and a second antenna array which are respectively composed of a plurality of first microstrip reflecting units and a plurality of second microstrip reflecting units, and the second antenna array surrounds the first antenna array. In addition, the spacing between the first microstrip reflection units is smaller than the spacing between the second microstrip reflection units.

Description

Partially reflective antenna

technical field

The invention relates to a partial reflector antenna, in particular to a partial reflector antenna comprising a reflector composed of a microstrip antenna array and having the advantages of low side lobe and high gain.

Background technique

In recent years, a Partial Reflective Surface Antenna (Partial Reflective Surface Antenna) having a Partial Reflective Surface (PRS) composed of a microstrip antenna array has been widely used in both military and civilian applications. These partially reflector antennas have the advantages of low profile and can be fabricated using printed circuit boards.

But even so, the high-frequency signals emitted by these partially reflective antennas still have significant side lobe parts, and the ratio of them to the overall waveform cannot be further reduced. This phenomenon not only prevents the strength of the high-frequency signal provided by the part of the reflector antenna in its main beam direction from being further improved, but also limits the transmission distance. In addition, its antenna gain (gain) cannot continue to increase as the area of the antenna increases, that is, when its area is greater than an optimal area (optimum area), its efficiency (ie, the gain per unit area) Instead, it decreases as the antenna area increases. The efficiency of currently known partial reflector antennas is only about 50% at best.

FIG. 1 is a schematic perspective view of a known partial reflector antenna, wherein the partial reflector antenna 1 includes a substrate 11 and a reflector 12, both of which are made of a microwave substrate made of FR-4 material. The reflecting plate 12 is kept a resonance distance (resonant distance) with the upper surface 111 of the substrate 11 by the first support rod 141, the second support rod 142, the third support rod 143 and the fourth support rod 144. And it is related to the design frequency of the partial reflector antenna 1 . In addition, there is a rectangular slot (not shown) in the center of the substrate 11 , and the rectangular slot is electrically connected to a coaxial cable to output or receive a high frequency signal.

When the partially reflective antenna is in its transmitting state, the high-frequency signal is reflected back and forth between the substrate 11 and the reflector 12, and with the help of the "partial reflection" effect caused by the reflector 12, the high-frequency signal is finally It penetrates the reflector 12 and is emitted by the partial reflector antenna 1 . The length (L) and width (W) of the reflection plate 12 are both 12.9 cm, and a plurality of microstrip reflection units 13 are evenly arranged on the upper surface 121 thereof. The length (L) and width (W) of each microstrip reflective unit are both 12 mm, and the distance between each microstrip reflective unit and the adjacent microstrip reflective unit 13 is 1.1 mm.

As mentioned above, although the known partial reflector antenna 1 can be positioned at the arrangement mode of the microstrip reflection unit 13 (adjusting the spacing between each microstrip reflection unit 13 ) on the upper surface 121 of its reflection plate 12 by properly adjusting, the improvement can be achieved. The signal/noise ratio and directivity of the high-frequency signal it emits. However, the ratio and gain of the "side lobe" portion of the high-frequency signal output by the known partial reflector antenna 1 to the overall waveform cannot be further reduced and improved by this method.

Therefore, the industry urgently needs a partially reflective antenna with the advantages of "low side lobe" and "high gain" to further improve the performance of the antenna module of the wireless communication system.

Contents of the invention

The object of the present invention is to provide a partial reflector antenna.

In order to achieve the above object, the partial reflector antenna provided by the present invention is used to receive and output a high-frequency signal, including:

A substrate with an upper surface, and a signal output port opened on the upper surface for receiving and outputting the high-frequency signal;

a reflector for partially reflecting the high-frequency signal, the surface of the reflector is provided with a first antenna array and a second antenna array, and the second antenna array surrounds the first antenna array; and

a plurality of supporting units, the supporting units support the reflective plate on the upper surface of the substrate, and maintain a specific distance between the reflective plate and the substrate;

Wherein, the first antenna array is composed of a plurality of first microstrip reflection units, and the second antenna array is composed of a plurality of second microstrip reflection units; the distance between the first microstrip reflection units is smaller than that between the first microstrip reflection units equal to the spacing between the second microstrip reflective units.

Wherein the substrate is a microwave substrate made of FR-4 material.

Wherein the reflecting plate is a microwave substrate made of FR-4 material.

Wherein the shape of the first microstrip reflective units is square.

Wherein the shape of the second microstrip reflective units is square.

Wherein the appearance of the first microstrip reflective units is strip-shaped.

Wherein the appearance of the second microstrip reflective units is strip-shaped.

Wherein the supporting units are made of insulating material.

The frequency range of the high-frequency signal is between 9GHz and 10GHz.

Wherein the reflecting plate is a square plate.

Wherein the specific distance is half of the wavelength of the high frequency signal.

Wherein the signal output inlet is a rectangular slot.

Wherein the signal output port is electrically connected to a coaxial cable.

The above-mentioned partial reflector antenna of the present invention reduces the ratio of the "side lobe" of the high-frequency signal emitted by it by arranging two antenna arrays with different arrangements on the surface of the reflector, so that the The energy of the high-frequency signal can be more concentrated in its main lobe (main lobe), so that the high-frequency signal can not only transmit a longer distance, but is also less likely to be interfered. In addition, the partial reflector antenna of the present invention can further increase its gain compared with the known partial reflector antenna, so that an antenna module using the partial reflector antenna of the present invention has better performance.

Description of drawings

FIG. 1 is a schematic perspective view of a known partial reflector antenna.

FIG. 2A is a perspective view of a partial reflector antenna according to a first preferred embodiment of the present invention.

FIG. 2B is a schematic diagram of the reflector of the partial reflector antenna according to the first preferred embodiment of the present invention.

2C is a schematic diagram showing the arrangement of the first antenna array and the second antenna array respectively located on the reflector surface of the partial reflector antenna according to the first preferred embodiment of the present invention.

FIG. 3A is a schematic diagram of a reflector of a first known partially reflective surface antenna.

FIG. 3B is a schematic diagram showing the arrangement of the microstrip reflective units on the surface of the reflective plate shown in FIG. 3A .

FIG. 4A is a schematic diagram of waveforms on the magnetic field plane of the high-frequency signal emitted by the first conventional partial reflector antenna and the high-frequency signal emitted by the partial reflector antenna of the first preferred embodiment of the present invention.

4B is a schematic diagram of waveforms on the electric field plane of the high frequency signal emitted by the first known partial reflector antenna and the high frequency signal emitted by the partial reflector antenna of the first preferred embodiment of the present invention.

FIG. 4C is a schematic diagram of gain distributions in various frequency ranges of the first conventional partial reflector antenna and the partial reflector antenna according to the first preferred embodiment of the present invention.

FIG. 5A is a schematic diagram of a reflector of a second known partial reflector antenna.

FIG. 5B is a schematic diagram showing the arrangement of the microstrip reflective units on the surface of the reflective plate shown in FIG. 5A .

6A is a schematic diagram of the waveforms of the high-frequency signal emitted by the second conventional partial reflector antenna and the high-frequency signal emitted by the partial reflector antenna of the first preferred embodiment of the present invention on the magnetic field plane.

FIG. 6B is a schematic waveform diagram of the high-frequency signal emitted by the second conventional partial reflector antenna and the high-frequency signal emitted by the partial reflector antenna of the first preferred embodiment of the present invention on the electric field plane.

6C is a schematic diagram of the gain distributions of the second conventional partial reflector antenna and the partial reflector antenna of the first preferred embodiment of the present invention in various frequency ranges.

FIG. 7A is a schematic diagram of a reflector of a partial reflector antenna according to a second preferred embodiment of the present invention.

7B is a schematic view showing the arrangement of the first antenna array and the second antenna array respectively located on the reflector surface of the partial reflector antenna according to the second preferred embodiment of the present invention.

Detailed ways

Fig. 2A is the three-dimensional schematic view of the partial reflector antenna of the first preferred embodiment of the present invention, wherein the partial reflector antenna 2 includes a substrate 21 and a reflector 22, both of which are microwave substrates made of FR-4 material with a thickness of 0.8mm constitute. The reflection plate 22 maintains a resonant distance from the upper surface 211 of the substrate 21 by the first support rod 241 , the second support rod 242 , the third support rod 243 and the fourth support rod 244 . The length of this resonance distance is related to the design frequency of the partial reflector antenna 2. When the design frequency (design frequency) is 9.3GHz, this resonance distance is about 1.68cm; and when the design frequency is 9.5GHz, this resonance distance It is about 1.65cm.

In addition, the center of the substrate 21 has a rectangular slot (not shown in the figure), and the rectangular slot is electrically connected to a coaxial cable to output or receive a high-frequency signal with a frequency range between 9.25 GHz and 9.55 GHz. . When the partially reflective antenna of the first preferred embodiment of the present invention is in its transmitting state, the high-frequency signal is reflected back and forth between the substrate 21 and the reflector 22, and passes through the "partial reflection" effect caused by the reflector 22 With assistance, the high-frequency signal finally penetrates the reflector 22 and is emitted by the partial reflector antenna 2 .

As shown in FIG. 2B and FIG. 2C , the length and width of the reflecting plate 22 are both 17.8 cm, and its surface area is 316.84 cm ² . The upper surface 221 of the reflecting plate 22 is provided with two kinds of antenna arrays with different spacings, ie, the first antenna array and the second antenna array. In these two antenna arrays, the length (L) and width (W) of the first microstrip reflection unit 231 and the second microstrip reflection unit 232 of the constituent units are 12mm, but they are different from the adjacent microstrip reflection unit The spacing between them is not the same. That is, in the first antenna array, the distance (Dx1) between each first microstrip reflection unit 231 and the adjacent first microstrip reflection unit 231 in the X direction and the distance (Dy1) in the Y direction Both are 1.1 mm (Dx1=Dy1=1.1 mm). But in the second antenna array, the spacing (Dx2) in the X direction and the spacing (Dy2) in the Y direction between each second microstrip reflecting unit 232 and the adjacent second microstrip reflecting unit 232 are both 3.14mm (Dx2=Dy2=3.14mm).

FIG. 3A is a schematic diagram of a reflector of the first known partial reflector antenna, and FIG. 3B is a schematic diagram showing the arrangement of microstrip reflectors on the surface of the reflector. Wherein, the reflecting plate 31 is made of a microwave substrate made of FR-4 material with a thickness of 0.8 mm, its length and width are both 12.9 cm, and its surface area is 166.41 cm ² . A plurality of microstrip reflection units 33 are evenly arranged on the upper surface 32 of the reflection plate 31 . The length (L) and width (W) of each microstrip reflection unit 33 are 12 mm, and there is a distance (Dx1) in the X direction between each microstrip reflection unit 33 and adjacent microstrip reflection units 33 The distances (Dy1) from the Y direction are all 1.1 mm (Dx1=Dy1=1.1 mm).

Next, the partial reflector antenna of the first preferred embodiment of the present invention will be compared with the above-mentioned first known partial reflector antenna, that is, the characteristics of the high-frequency signals emitted by the two are compared, such as side wave Lobe (sidelobe level) and gain (gain), which can prove that the partial reflector antenna of the first preferred embodiment of the present invention has "low sidelobe" and "high gain" advantage.

In Fig. 4A, Fig. 4B and Fig. 4C, the characteristic of the high-frequency signal emitted by the partial reflector antenna of the first preferred embodiment of the present invention is represented by the "the third PRS" curve, and the aforementioned first known The characteristics of the high-frequency signal emitted by the partial reflector antenna are represented by the "the first PRS" curve. Among them, Fig. 4A shows the high-frequency signal (frequency is 9.3 GHz) emitted by the aforementioned first known partial reflector antenna and the high-frequency signal emitted by the partial reflector antenna of the first preferred embodiment of the present invention ( The frequency is 9.3GHz) on the magnetic field plane (H-plane) waveform schematic diagram. Fig. 4B is the high-frequency signal (frequency 9.3 GHz) emitted by the aforementioned first known partial reflector antenna and the high-frequency signal (frequency 9.3 GHz) emitted by the partial reflector antenna of the first preferred embodiment of the present invention. 9.3 GHz) waveform diagram on the electric field plane (E-plane).

As can be seen from Fig. 4A and Fig. 4B, the waveform (the third PRS) of the high-frequency signal emitted by the partial reflector antenna of the first preferred embodiment of the present invention is better than that of the aforementioned first known partial reflector antenna. The waveform of the emitted high-frequency signal (the first PRS) is concentrated, especially the waveform on the magnetic field plane is the most obvious. Therefore, compared with the aforementioned first known partial reflector antenna, the partial reflector antenna in the first preferred embodiment of the present invention can effectively reduce the "side lobe" portion of the high-frequency signal emitted by it as a whole. The ratio of the waveform, and the energy of the high-frequency signal emitted by it is more concentrated in its main lobe (main lobe) part. In this way, the high-frequency signal emitted by the partial reflector antenna in the first preferred embodiment of the present invention can not only transmit a longer distance, but also be less susceptible to external interference.

FIG. 4C is a schematic diagram of gain distributions in various frequency ranges of the aforementioned first known partial reflector antenna and the partial reflector antenna according to the first preferred embodiment of the present invention. Among them, the maximum gain frequencies of the two partial reflector antennas are close to 9300MHz (9.3GHz).

As can be seen from Fig. 4C, in the entire frequency range (8800MHz to 10300MHz), the gain (gain) of the partial reflector antenna of the first preferred embodiment of the present invention is greater than that of the aforementioned first known partial reflector antenna gain. After proper calculation, the efficiency (i.e. the gain per unit area) of the aforementioned first known partial reflector antenna can be about 51%, and the efficiency of the partial reflector antenna of the first preferred embodiment of the present invention Also around 51%.

In addition, since the reflector used by the aforementioned first type of known partial reflector antenna is just the same as the part covered by the first antenna array of the reflector of the partial reflector antenna in the first preferred embodiment of the present invention. That is to say, the reflector of the partial reflector antenna in the first preferred embodiment of the present invention is equivalent to adding a second array of loosely arranged antennas around the reflector used in the aforementioned first known partial reflector antenna. . The slightly increased area reduces the side lobe and increases the gain of the signal emitted by the partial reflector antenna according to the first preferred embodiment of the present invention. Its further meaning is that the loss of the substrate and conductors does not reduce the efficiency of the antenna due to the increase in the area, such as the efficiency of the partial reflector antenna in the first preferred embodiment of the present invention remains unchanged.

To sum up, as shown in Fig. 4A to Fig. 4C, the mode of forming the reflector by adding a relatively loosely arranged second antenna array to the reflector equivalent to the aforementioned first known partial reflector antenna is the first method of the present invention. Compared with the above-mentioned first known partial reflector antenna, the partial reflector antenna of a preferred embodiment can significantly reduce the ratio of the "side lobe" part of the high-frequency signal emitted by it to the overall waveform, so that high The energy of the frequency signal is more concentrated in its main lobe, without affecting its overall efficiency (still about 51%). This specification will present the reflector of the second known partial reflector antenna below to show that the partial reflector antenna of the first preferred embodiment of the present invention can improve the efficiency of the antenna under the condition that the area of the reflector is approximately the same .

FIG. 5A is a schematic diagram of a reflector of a second known partial reflector antenna, and FIG. 5B is a schematic diagram showing the arrangement of microstrip reflectors on the surface of the reflector. Wherein, the reflection plate 51 is made of a microwave substrate made of FR-4 material with a thickness of 0.8 mm, its length and width are 19.4 cm and 16.9 cm, respectively, and its surface area is 327.86 cm ² . A plurality of microstrip reflection units 53 are evenly arranged on the upper surface 52 of the reflection plate 51 . The length (L) and width (W) of each microstrip reflection unit 53 are 12 mm, and there is a distance (Dx1) in the X direction between each microstrip reflection unit 53 and adjacent microstrip reflection units 53 The distances (Dy1) from the Y direction are all 1.1 mm (Dx1=Dy1=1.1 mm).

Next, the partial reflector antenna of the first preferred embodiment of the present invention will be compared with the aforementioned second known partial reflector antenna, that is, the characteristics of the high-frequency signals emitted by the two are compared, such as side wave Lobe and gain, which can prove that the partial reflector antenna of the first preferred embodiment of the present invention also has the advantages of "low side lobe" and "high gain" compared with the aforementioned second type of known partial reflector antenna.

In Fig. 6A, Fig. 6B and Fig. 6C, the characteristic of the high-frequency signal emitted by the partial reflector antenna of the first preferred embodiment of the present invention is represented by the "the third PRS" curve, and the aforementioned second known The characteristics of the high-frequency signal emitted by the partial reflector antenna are represented by the "the secondPRS" curve. Among them, Fig. 6A shows the high-frequency signal (frequency is 9.3 GHz) emitted by the aforementioned second type of known partial reflector antenna and the high-frequency signal emitted by the partial reflector antenna of the first preferred embodiment of the present invention ( The frequency is 9.3GHz) and the schematic diagram of the waveform on the magnetic field plane. Fig. 6B is the high-frequency signal (frequency of 9.3 GHz) emitted by the aforementioned second known partial reflector antenna and the high-frequency signal (frequency of 9.3 GHz) emitted by the partial reflector antenna of the first preferred embodiment of the present invention. 9.3GHz) waveform diagram on the electric field plane.

As can be seen from Fig. 6A and Fig. 6B, the waveform (the third PRS) of the high-frequency signal emitted by the partial reflector antenna of the first preferred embodiment of the present invention is better than that of the aforementioned second known partial reflector antenna. The waveform of the emitted high-frequency signal (the second PRS) is concentrated, especially the waveform on the magnetic field plane is the most obvious. Therefore, compared with the aforementioned second known partial reflector antenna, the partial reflector antenna in the first preferred embodiment of the present invention can effectively reduce the "side lobe" portion of the high-frequency signal emitted by it as a whole. The ratio of the waveform, and the energy of the high-frequency signal emitted by it is more concentrated in its main lobe. In this way, the high-frequency signal emitted by the partial reflector antenna of the first preferred embodiment of the present invention can not only transmit a longer distance, but also be less susceptible to external interference.

FIG. 6C is a schematic diagram of the gain distribution in each frequency range of the aforementioned second conventional partial reflector antenna and the partial reflector antenna according to the first preferred embodiment of the present invention. Among them, the maximum gain frequencies of the two partial reflector antennas are close to 9300MHz (9.3GHz).

As can be seen from Fig. 6C, in the entire frequency range (8800MHz to 10300MHz), the gain (gain) of the partial reflector antenna of the first preferred embodiment of the present invention is greater than that of the aforementioned second known partial reflector antenna gain.

After proper calculation, it can be concluded that the efficiency (i.e. the gain per unit area) of the aforementioned second known partial reflector antenna is about 41%, which is far lower than that of the partial reflector of the first preferred embodiment of the present invention The efficiency of the antenna (about 51%). Therefore, although the reflector area (316.84cm ² ) of the partial reflector antenna of the first preferred embodiment of the present invention is smaller than the reflector area (327.86cm ² ) of the aforementioned second known partial reflector antenna, it is The gain of the whole frequency range (8800MHz to 10300MHz) is still greater than that of the aforementioned second type of known partial reflector antenna.

In summary, as shown in FIG. 6A to FIG. 6C , the partial reflector antenna according to the first preferred embodiment of the present invention still has the advantage of "high gain" compared with the aforementioned second type of known partial reflector antenna.

7A is a schematic diagram of a reflector of a partial reflector antenna according to a second preferred embodiment of the present invention, and FIG. 7B is a schematic diagram showing the arrangement of the first antenna array and the second antenna array respectively located on the surface of the reflector. As shown in FIG. 7A and FIG. 7B , the length and width of the reflection plate 71 are 16.8 cm and 16.5 cm, and are made of a microwave substrate made of FR-4 material with a thickness of 0.8 mm. The upper surface 72 of the reflecting plate 71 is provided with two kinds of antenna arrays with different spacings, ie, a first antenna array and a second antenna array. In these two antenna arrays, the dimensions of the first microstrip reflection unit 731 and the second microstrip reflection unit 732 are the same, and their length (L) and width (W) are 17.25mm and 0.75mm respectively, but The X-direction spacing between them and adjacent microstrip reflective units is not the same. That is, in the first antenna array, the X-direction spacing (Dx1) between each first microstrip reflection unit 731 and the adjacent first microstrip reflection unit 731 is 0.75mm, and the Y-direction spacing (Dy2 ) is also 0.75mm. However, in the second antenna array, the X-direction spacing (Dx2) existing between each second microstrip reflection unit 732 and the adjacent second microstrip reflection unit 732 is 2.25 mm, and the Y-direction spacing (Dy2 ) is 1.6mm.

Because the three-dimensional structure of the partial reflector antenna of the second preferred embodiment of the present invention having reflector 71 is similar to the three-dimensional structure of the partial reflector antenna of the first preferred embodiment of the present invention shown in Fig. 2A, its operating principle Also the same. Moreover, the difference between the two is only the size of the reflector, the shapes of the first microstrip reflector and the second microstrip reflector (square vs. rectangle), and the position of the rectangular slot on the substrate. Therefore, the three-dimensional structure and operating principle of the partial reflector antenna in the second preferred embodiment of the present invention will not be repeated here, and are hereby described. That is to say, the partial reflector antenna according to the second preferred embodiment of the present invention also has the advantages of "low side lobe" and "high gain" compared with the known partial reflector antenna.

In summary, compared with the high-frequency signals emitted by the known partial reflector antenna, the high-frequency signal emitted by the partial reflector antenna of the present invention not only has the "side lobe" part of the overall waveform The lower the ratio, the higher the antenna gain. Therefore, the performance of an antenna module using the partial reflector antenna of the present invention can be further improved.

The above-mentioned embodiments are only examples for convenience of description, and the scope of rights claimed by the present invention should be based on the scope of the patent application, rather than limited to the above-mentioned embodiments.

Claims (12)

1. A partial reflector antenna for receiving and outputting a high-frequency signal, comprising: A substrate with an upper surface, and a signal output port opened on the upper surface for receiving and outputting the high-frequency signal; a reflector for partially reflecting the high-frequency signal, the surface of the reflector is provided with a first antenna array and a second antenna array, and the second antenna array surrounds the first antenna array; and a plurality of supporting units, the supporting units support the reflecting plate on the upper surface of the substrate, and maintain a distance of one-half of the wavelength of the high-frequency signal between the reflecting plate and the substrate; Wherein, the first antenna array is composed of a plurality of first microstrip reflection units, and the second antenna array is composed of a plurality of second microstrip reflection units; the distance between the first microstrip reflection units is smaller than that between the first microstrip reflection units equal to the spacing between the second microstrip reflective units. 2. The partial reflector antenna according to claim 1, wherein the substrate is a microwave substrate made of FR-4 material. 3. The partial reflector antenna according to claim 1, wherein the reflector is a microwave substrate made of FR-4. 4. The partial reflector antenna as claimed in claim 1, wherein the shape of the first microstrip reflecting elements is a square. 5 . The partial reflector antenna as claimed in claim 1 , wherein the shape of the second microstrip reflectors is square. 6 . 6 . The partial reflector antenna as claimed in claim 1 , wherein the first microstrip reflectors are strip-shaped. 7 . 7. The partial reflector antenna as claimed in claim 1, wherein the shape of the second microstrip reflective elements is a strip shape. 8. The partial reflector antenna as claimed in claim 1, wherein the supporting units are made of insulating material. 9. The partial reflector antenna as claimed in claim 1, wherein the frequency range of the high frequency signal is between 9 GHz and 10 GHz. 10. The partial reflector antenna as claimed in claim 1, wherein the reflector is a square plate. 11. The partial reflector antenna according to claim 1, wherein the signal output inlet is a rectangular slot. 12. The partial reflector antenna according to claim 1, wherein the signal output port is electrically connected to a coaxial cable.

Images