Dual-frequency circularly polarized fusion antenna with large frequency ratio and design method thereof

Abstract

This invention discloses a dual-frequency circularly polarized fusion antenna with a high frequency ratio and its design method. It includes a first and a second dielectric substrate, with the first substrate positioned above the second. The lower surface of the first substrate is a copper-clad ground plane, and its upper surface is provided with a first, second, third, and fourth metal radiator. A metal post is loaded at one end of each radiator near the center of the dielectric substrate and connected to the ground plane, while a millimeter-wave metal probe is loaded at the other end away from the center. The lower surface of the second dielectric substrate has a microwave feed network and four 180-degree phase difference power dividers. The output ports of the microwave feed network are connected to the four microwave metal probes, and the output ports of the 180-degree phase difference power dividers are connected to eight millimeter-wave metal probes. This invention features dual-frequency circular polarization, effectively reducing the impact of multipath effects and enabling the reuse of radiators, thereby reducing the space resource requirements of communication equipment.

Description

Technical Field

[0001] This invention relates to the technical field of fusion antennas, and in particular to a dual-frequency circularly polarized fusion antenna with a large frequency ratio and its design method. Background Technology

[0002] Millimeter-wave communication technology, as a key component of 5G technology, boasts significant bandwidth and transmission speed advantages, meeting the demands of high-speed data transmission. However, millimeter-wave communication is susceptible to obstruction and has limited coverage during transmission, which restricts its widespread application. Currently, low-Earth orbit (LEO) satellites are moving towards integrated communication and navigation development. By combining communication and navigation functions, LEO satellites can achieve higher-quality, higher-speed communication and precise positioning services. Furthermore, reusable satellite resources can provide low-cost, wide-coverage, and high-performance integrated communication and navigation services for the low-altitude economy.

[0003] Currently, most 5G communication antennas and satellite navigation antennas are designed separately and then packaged in the same communication device. This results in a large device size and high space resource requirements, hindering its further development. Common-aperture antennas can integrate antenna elements of different frequency bands onto the same dielectric substrate, reducing the space resource requirements of the communication device. However, coupling effects between antenna elements of different frequency bands are inevitable, thus affecting antenna performance. Therefore, the dual-frequency circular polarization of this invention multiplexes a millimeter-wave band antenna array into a microwave band radiator, solving the problem of limited space resources in communication devices. The dual-frequency circular polarization also reduces the impact of multipath effects, improving communication quality. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings and deficiencies of the prior art and to propose a dual-frequency circularly polarized fusion antenna with a large frequency ratio and its design method. This antenna has the advantages of cross-frequency band and multiplexing of radiating structure. It has high-gain circular polarization performance in the 5G millimeter-wave band. The entire millimeter-wave array is multiplexed into a microwave circularly polarized patch antenna operating in the BeiDou B1 band, which can realize the fusion of BeiDou satellite positioning and 5G millimeter-wave communication.

[0005] To achieve the above objectives, the technical solution provided by this invention is as follows: a dual-frequency circularly polarized fusion antenna with a high frequency ratio, comprising a first dielectric substrate, a second dielectric substrate, a first metal radiator, a second metal radiator, a third metal radiator, and a fourth metal radiator; the first dielectric substrate is stacked on top of the second dielectric substrate; a copper-clad layer is disposed on the lower surface of the first dielectric substrate as a metal ground plane; the first, second, third, and fourth metal radiators are all disposed on the upper surface of the first dielectric substrate and are distributed in a 90-degree rotational arrangement around the center of the upper surface of the first dielectric substrate; a microwave feed network, a first 180-degree phase difference power divider, a second 180-degree phase difference power divider, a third 180-degree phase difference power divider, and a fourth 180-degree phase difference power divider are disposed on the lower surface of the second dielectric substrate. A 0-degree phase difference power divider; the first metal radiator is connected to the first 180-degree phase difference power divider via a first millimeter-wave metal probe, the second metal radiator is connected to the second 180-degree phase difference power divider via a second millimeter-wave metal probe, the third metal radiator is connected to the third 180-degree phase difference power divider via a third millimeter-wave metal probe, and the fourth metal radiator is connected to the fourth 180-degree phase difference power divider via a fourth millimeter-wave metal probe; the first metal radiator is connected to the microwave feed network via a first microwave metal probe, the second metal radiator is connected to the microwave feed network via a second microwave metal probe, the third metal radiator is connected to the microwave feed network via a third microwave metal probe, and the fourth metal radiator is connected to the microwave feed network via a fourth microwave metal probe.

[0006] Preferably, the fourth metal radiator includes a first rectangular metal patch, a second rectangular metal patch, and a first rectangular metal strip, a second rectangular metal strip, a third rectangular metal strip, and a fourth rectangular metal strip located between the first and second rectangular metal patches. The first rectangular metal strip, the second rectangular metal strip, the third rectangular metal strip, and the fourth rectangular metal strip are distributed at intervals along the length direction of the first and second rectangular metal patches. The first rectangular metal patch and the second rectangular metal patch are connected by the first rectangular metal strip, the second rectangular metal strip, the third rectangular metal strip, and the fourth rectangular metal strip. The structures of the first metal radiator, the second metal radiator, and the third metal radiator are the same as those of the fourth metal radiator. The second metal radiator is obtained by symmetrically positioning the fourth metal radiator about the center of the upper surface of the first dielectric substrate. The first metal radiator and the third metal radiator are obtained by rotating the second metal radiator and the fourth metal radiator clockwise by 90 degrees about the center of the upper surface of the first dielectric substrate.

[0007] Preferably, the first metal radiator is connected to the metal ground plane via a first metal pillar group, the second metal radiator is connected to the metal ground plane via a second metal pillar group, the third metal radiator is connected to the metal ground plane via a third metal pillar group, and the fourth metal radiator is connected to the metal ground plane via a fourth metal pillar group, so as to ensure that the first, second, third, and fourth metal radiators form a cascaded triangular cavity standing wave radiation in the millimeter-wave frequency band and operate as a quarter-wavelength patch antenna with a short-circuited terminal in the microwave frequency band.

[0008] Preferably, the first, second, third, and fourth 180-degree phase difference power dividers are all loaded with high-pass filters; each of the first, second, third, and fourth 180-degree phase difference power dividers includes a millimeter-wave input port, a first millimeter-wave output port, a second millimeter-wave output port, a millimeter-wave 180-degree phase shifter, and a millimeter-wave quarter-wave impedance transformer. The millimeter-wave input port is connected to the millimeter-wave quarter-wave impedance transformer via a transmission line. The millimeter-wave quarter-wave impedance transformer is connected to the millimeter-wave 180-degree phase shifter and the high-pass filter via transmission lines, respectively. The millimeter-wave 180-degree phase shifter is connected to the high-pass filter via a transmission line. The high-pass filter is connected to the first and second millimeter-wave output ports, respectively.

[0009] Preferably, the microwave feeding network includes a microwave input port, a first microwave output port, a second microwave output port, a third microwave output port, a fourth microwave output port, a microwave quarter-wavelength impedance transformer, a first 90-degree phase shifter, a second 90-degree phase shifter, and a microwave 180-degree phase shifter; the first microwave output port is connected to a first microwave metal probe to feed a first metal radiator, the second microwave output port is connected to a second microwave metal probe to feed a second metal radiator, the third microwave output port is connected to a third microwave metal probe to feed a third metal radiator, and the fourth microwave output port is connected to a fourth microwave metal probe to feed a fourth metal radiator; the microwave input port is connected to the microwave quarter-wavelength impedance transformer via a transmission line, the microwave quarter-wavelength impedance transformer is connected to the first microwave output port, the first 90-degree phase shifter, and the microwave 180-degree phase shifter via transmission lines, the microwave 180-degree phase shifter is connected to the third microwave output port and the second 90-degree phase shifter via transmission lines, the second microwave output port is loaded onto the first 90-degree phase shifter, and the fourth microwave output port is loaded onto the second 90-degree phase shifter.

[0010] Preferably, the first metal radiator, the second metal radiator, the third metal radiator, the fourth metal radiator, the microwave feed network, the first 180-degree phase difference power divider, the second 180-degree phase difference power divider, the third 180-degree phase difference power divider, and the fourth 180-degree phase difference power divider are all copper-clad layers.

[0011] Preferably, the first microwave metal probe, the second microwave metal probe, the third microwave metal probe, the fourth microwave metal probe, the first metal column group, the second metal column group, the third metal column group, the fourth metal column group, the first millimeter-wave metal probe, the second millimeter-wave metal probe, the third millimeter-wave metal probe, and the fourth millimeter-wave metal probe are all copper metal columns.

[0012] Preferably, when the microwave input port of the microwave feed network is excited, the dual-frequency circularly polarized fusion antenna operates in the microwave frequency band, and a single radiator is equivalent to a quarter-wavelength terminal short-circuit patch antenna; when the first 180-degree phase difference power divider is excited with 0-degree phase, the second 180-degree phase difference power divider with 90-degree phase, the third 180-degree phase difference power divider with 180-degree phase, and the fourth 180-degree phase difference power divider with 270-degree phase, the dual-frequency circularly polarized fusion antenna operates in the millimeter-wave frequency band, and a single radiator is equivalent to a 2×7 cascaded triangular cavity array.

[0013] This invention also provides a design method for the above-mentioned dual-frequency circularly polarized fusion antenna with a large frequency ratio, comprising the following steps:

[0014] Select the microwave frequency f1 and the millimeter wave frequency f2 as the operating center frequencies;

[0015] Calculate frequency ratio Determine the number of cascaded triangular cavities. Determine the number of rectangular metal strips Therefore, the number of rectangular metal strips can be obtained from the frequency ratio:

[0016] Determine the length L and width W of the rectangular metal patch. Width W can be derived from We get the value where C0 is the speed of light in a vacuum, and ε is the velocity of light in a vacuum. r The dielectric constant of the dielectric substrate;

[0017] Two rectangular metal patches are mirrored and connected with rectangular metal strips to obtain a metal radiator. The metal radiator is then symmetrical about the top surface of the first dielectric substrate. The two symmetrical metal radiators are then rotated 90 degrees clockwise about the top surface of the first dielectric substrate to obtain four metal radiators.

[0018] A metal pillar assembly is loaded at one end of the metal radiator near the center of the first dielectric substrate, a millimeter-wave metal probe is loaded at the other end away from the center of the first dielectric substrate, and a microwave metal probe is loaded at the center of the rectangular metal strip near the center of the first dielectric substrate.

[0019] A copper layer is applied to the lower surface of the first dielectric substrate to serve as a metal ground plane in contact with the metal pillar assembly. A microwave feed network and four 180-degree phase difference power dividers are designed on the lower surface of the second dielectric substrate. The output ports of the microwave feed network have phase differences of 0 degrees, 90 degrees, 180 degrees, and 270 degrees, and are connected to microwave metal probes. Each 180-degree phase difference power divider is loaded with a high-pass filter, and its output port is connected to a millimeter-wave metal probe.

[0020] When four 180-degree phase difference power dividers are excited with phase characteristics of 0 degrees, 90 degrees, 180 degrees, and 270 degrees, a single radiator can operate in the millimeter-wave frequency band, and the radiation characteristics are those of a cascaded triangular cavity array with overall circular polarization characteristics.

[0021] When the microwave feed network is excited, a single radiator can be equivalent to a patch of a quarter wavelength of microwave, and the whole network has circular polarization characteristics.

[0022] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0023] 1. The antenna designed in this invention realizes the reuse of microwave and millimeter-wave radiation structures, increases the antenna aperture utilization rate, and can solve the problem of limited space resources in communication equipment.

[0024] 2. This invention achieves dual-band circular polarization characteristics by designing a microwave feed network and a 180-degree phase difference power divider, integrating BeiDou satellite positioning with 5G millimeter-wave communication, and the millimeter-wave band has high gain.

[0025] 3. This invention loads a high-pass filter onto a 180-degree phase difference power divider, which enhances the isolation between the microwave and millimeter-wave frequency bands. Attached Figure Description

[0026] Figure 1 A three-dimensional view of the fusion antenna designed for this invention.

[0027] Figure 2 A top view of the fusion antenna designed for this invention.

[0028] Figure 3 The diagram shows the microwave feed network and 180-degree phase difference power divider structure of the fusion antenna designed for this invention.

[0029] Figure 4 The S-parameter curve of the fusion antenna designed for the present invention in the millimeter-wave band.

[0030] Figure 5 A graph showing the axial ratio (AR) parameter of the fusion antenna designed for the millimeter-wave band in this invention.

[0031] Figure 6 The XOZ radiation pattern of the fusion antenna designed for this invention at a center frequency of 24.6 GHz in the millimeter-wave band.

[0032] Figure 7 The radiation pattern of the fusion antenna designed for this invention in the YOZ plane at a center frequency of 24.6 GHz in the millimeter wave band.

[0033] Figure 8 The S-parameter curve of the fusion antenna designed for the present invention in the microwave band.

[0034] Figure 9 A graph showing the axial ratio (AR) parameter of the fusion antenna designed for the present invention in the microwave band.

[0035] Figure 10 The XOZ radiation pattern of the fusion antenna designed for this invention at a center frequency of 1.56 GHz in the microwave band.

[0036] Figure 11 The radiation pattern of the fusion antenna designed for this invention in the YOZ plane at a center frequency of 1.56 GHz in the microwave band. Detailed Implementation

[0037] The present invention will be further described in detail below with reference to the embodiments and accompanying drawings, but the embodiments of the present invention are not limited thereto.

[0038] like Figure 1 and Figure 2As shown, this embodiment discloses a dual-frequency circularly polarized fusion antenna with a large frequency ratio, including a first dielectric substrate 1, a second dielectric substrate 2, a first metal radiator 71, a second metal radiator 72, a third metal radiator 73, and a fourth metal radiator 74; the first metal radiator 71 and the third metal radiator 73 are centrally symmetrically distributed about the center of the upper surface of the first dielectric substrate 1, and the second metal radiator 72 and the fourth metal radiator 74 are centrally symmetrically distributed about the center of the upper surface of the first dielectric substrate 1; the lower surface of the first dielectric substrate 1 is a copper-clad layer serving as a metal ground plane 11. The first metal radiator 71, the second metal radiator 72, the third metal radiator 73, and the fourth metal radiator 74 are connected to the metal ground plane 11 via the first metal pillar group 61, the second metal pillar group 62, the third metal pillar group 63, and the fourth metal pillar group 64, respectively. The ends of the first metal radiator 71, the second metal radiator 72, the third metal radiator 73, and the fourth metal radiator 74 away from the center of the first dielectric plate 1 are connected to the first millimeter-wave metal probe 81, the second millimeter-wave metal probe 82, the third millimeter-wave metal probe 83, and the fourth millimeter-wave metal probe 84, respectively.

[0039] Specifically, the fourth metal radiator 74 includes a first rectangular metal patch 741, a second rectangular metal patch 742, and a first rectangular metal strip 12, a second rectangular metal strip 13, a third rectangular metal strip 14, and a fourth rectangular metal strip 15 located between the first rectangular metal patch 741 and the second rectangular metal patch 742. The first rectangular metal strip 12, the second rectangular metal strip 13, the third rectangular metal strip 14, and the fourth rectangular metal strip 15 are spaced apart along the length direction of the first rectangular metal patch 741 and the second rectangular metal patch 742. The patch 742 is connected by a first rectangular metal strip 12, a second rectangular metal strip 13, a third rectangular metal strip 14, and a fourth rectangular metal strip 15; the structure of the first metal radiator 71, the second metal radiator 72, and the third metal radiator 73 is the same as that of the fourth metal radiator 74, and the second metal radiator 72 is obtained by symmetrically obtaining the fourth metal radiator 74 about the center of the upper surface of the first dielectric substrate 1; the first metal radiator 71 and the third metal radiator 73 are obtained by rotating the second metal radiator 72 and the fourth metal radiator 74 clockwise by 90 degrees about the center of the upper surface of the first dielectric substrate 1.

[0040] like Figure 3As shown, the lower surface of the second dielectric substrate 2 is designed with a microwave feed network 4 and a first 180-degree phase difference power divider 31, a second 180-degree phase difference power divider 32, a third 180-degree phase difference power divider 33, and a fourth 180-degree phase difference power divider 34. The output ports of the first 180-degree phase difference power divider 31, the second 180-degree phase difference power divider 32, the third 180-degree phase difference power divider 33, and the fourth 180-degree phase difference power divider 34 are respectively connected to the first millimeter-wave metal probe 81, the second millimeter-wave metal probe 82, the third millimeter-wave metal probe 83, and the fourth millimeter-wave metal probe 84. The first microwave output port 41, the second microwave output port 42, the third microwave output port 43, and the fourth microwave output port 44 of the microwave feed network 4 are respectively connected to the metal strips near the center of the first metal radiator 71, the second metal radiator 72, the third metal radiator 73, and the fourth metal radiator 74 via the first microwave metal probe 51, the second microwave metal probe 52, the third microwave metal probe 53, and the fourth microwave metal probe 54. The first 180-degree phase difference power divider 31, the second 180-degree phase difference power divider 32, the third 180-degree phase difference power divider 33, and the fourth 180-degree phase difference power divider 34 are all equipped with high-pass filters 9 to enhance the isolation between the microwave frequency band and the millimeter-wave frequency band.

[0041] Specifically, the first 180-degree phase difference power divider 31, the second 180-degree phase difference power divider 32, the third 180-degree phase difference power divider 33, and the fourth 180-degree phase difference power divider 34 each include a millimeter-wave input port 30, a first millimeter-wave output port 301, a second millimeter-wave output port 302, a millimeter-wave 180-degree phase shifter 303, and a millimeter-wave quarter-wave impedance transformer 304. The millimeter-wave input port 30 is connected to the millimeter-wave quarter-wave impedance transformer 304 via a transmission line. The millimeter-wave quarter-wave impedance transformer 304 is connected to the millimeter-wave 180-degree phase shifter 303 and a high-pass filter 9 via transmission lines. The millimeter-wave 180-degree phase shifter 303 is connected to the high-pass filter 9 via a transmission line. The high-pass filter 9 is connected to the first millimeter-wave output port 301 and the second millimeter-wave output port 302.

[0042] Specifically, the microwave feeding network 4 includes a microwave input port 40, a first microwave output port 41, a second microwave output port 42, a third microwave output port 43, a fourth microwave output port 44, a microwave quarter-wavelength impedance transformer 45, a first 90-degree phase shifter 46, a second 90-degree phase shifter 47, and a microwave 180-degree phase shifter 48. The first microwave output port 41 is connected to a first microwave metal probe 51 to feed the first metal radiator 71; the second microwave output port 42 is connected to a second microwave metal probe 52 to feed the second metal radiator 72; and the third microwave output port 43 is connected to a third microwave metal probe 53 to feed the third metal radiator 73. The fourth microwave output port 44 is connected to the fourth microwave metal probe 54 to power the fourth metal radiator 74; the microwave input port 40 is connected to the microwave quarter-wavelength impedance transformer 45 through a transmission line; the microwave quarter-wavelength impedance transformer 45 is connected to the first microwave output port 41, the first 90-degree phase shifter 46 and the microwave 180-degree phase shifter 48 through transmission lines; the microwave 180-degree phase shifter 48 is connected to the third microwave output port 43 and the second 90-degree phase shifter 47 through transmission lines; the second microwave output port 42 is loaded onto the first 90-degree phase shifter 46; and the fourth microwave output port 44 is loaded onto the second 90-degree phase shifter 47.

[0043] When the first 180-degree phase difference power divider 31 is excited with a 0-degree phase, the second 180-degree phase difference power divider 32 is excited with a 90-degree phase, the third 180-degree phase difference power divider 33 is excited with a 180-degree phase, and the fourth 180-degree phase difference power divider 34 is excited with a 270-degree phase, the dual-band circularly polarized fusion antenna operates in the millimeter-wave band with a center frequency of 24.6 GHz, and the radiator operates as a 2×7 cascaded triangular cavity array.

[0044] When the microwave feed network 4 is excited, the dual-frequency circularly polarized fusion antenna operates in the microwave band with a center frequency of 1.56 GHz, and the radiator operates as a quarter-wavelength terminal short-circuit patch.

[0045] Specifically, the first dielectric substrate 1 and the second dielectric substrate 2 are both 100mm in length and width, made of Rogers 5880 material with a dielectric constant of 2.2 and a loss tangent of 0.0009. The first dielectric substrate 1 has a thickness of 0.787mm, and the second dielectric substrate 2 has a thickness of 0.254mm. The first rectangular metal patch 741 and the second rectangular metal patch 742 have lengths and widths of 30.3mm and 3.15mm, respectively; the first rectangular metal strip 12, the second rectangular metal strip 13, the third rectangular metal strip 14, and the fourth rectangular metal strip 15 have lengths and widths of 1.85mm and 2.7mm, respectively, and the distance between adjacent metal strips is 6.65mm. The first metal radiator 71, the second metal radiator 72, the third metal radiator 73, and the fourth metal radiator 74 have lengths and widths of 30.3mm and 9mm, respectively. The metal pillars of the first metal pillar group 61, the second metal pillar group 62, the third metal pillar group 63, and the fourth metal pillar group 64 have a radius of 0.4 mm and a spacing of 1.1 mm. The first millimeter-wave metal probe 81, the second millimeter-wave metal probe 82, the third millimeter-wave metal probe 83, and the fourth millimeter-wave metal probe 84 have a radius of 0.19 mm. The first microwave metal probe 51, the second microwave metal probe 52, the third microwave metal probe 53, and the fourth microwave metal probe 54 have a radius of 0.3 mm. The microwave quarter-wave impedance transformer 45 of the microwave feed network 4 has a length of 32.375 mm, the first 90-degree phase shifter and the second 90-degree phase shifter have a length of 32.375 mm, and the microwave 180-degree phase shifter 48 has a length of 64.75 mm. The millimeter-wave 180-degree phase shifter 303 of the first 180-degree phase difference power divider 31, the second 180-degree phase difference power divider 32, the third 180-degree phase difference power divider 33, and the fourth 180-degree phase difference power divider 34 has a length of 4.1 mm, the millimeter-wave quarter-wave impedance transformer 304 has a length of 2.05 mm, and the high-pass filter 9 has a length of 2.21 mm.

[0046] The following is the design method of the dual-frequency circularly polarized fusion antenna described in this embodiment, and its process is as follows:

[0047] Select the microwave frequency f1 and the millimeter wave frequency f2 as the operating center frequencies;

[0048] Calculate frequency ratio Determine the number of cascaded triangular cavities. Determine the number of rectangular metal strips Therefore, the number of rectangular metal strips can be obtained from the frequency ratio:

[0049] Determine the length L and width W of the rectangular metal patch. Width W can be derived from We get the value where C0 is the speed of light in a vacuum, and ε is the velocity of light in a vacuum. rThe dielectric constant of the dielectric substrate;

[0050] Two rectangular metal patches are mirrored and connected with rectangular metal strips to obtain a metal radiator. The metal radiator is then symmetrical about the top surface of the first dielectric substrate. The two symmetrical metal radiators are then rotated 90 degrees clockwise about the top surface of the first dielectric substrate to obtain four metal radiators.

[0051] A metal pillar assembly is loaded at one end of the metal radiator near the center of the first dielectric substrate, a millimeter-wave metal probe is loaded at the other end away from the center of the first dielectric substrate, and a microwave metal probe is loaded at the center of the rectangular metal strip near the center of the first dielectric substrate.

[0052] A copper layer is applied to the lower surface of the first dielectric substrate to serve as a metal ground plane in contact with the metal pillar assembly. A microwave feed network and four 180-degree phase difference power dividers are designed on the lower surface of the second dielectric substrate. The output ports of the microwave feed network have phase differences of 0 degrees, 90 degrees, 180 degrees, and 270 degrees, and are connected to microwave metal probes. Each 180-degree phase difference power divider is loaded with a high-pass filter, and its output port is connected to a millimeter-wave metal probe.

[0053] When four 180-degree phase difference power dividers are excited with phase characteristics of 0 degrees, 90 degrees, 180 degrees, and 270 degrees, a single radiator can operate in the millimeter-wave frequency band, and the radiation characteristics are those of a cascaded triangular cavity array with overall circular polarization characteristics.

[0054] When the microwave feed network is excited, a single radiator can be equivalent to a patch of a quarter wavelength of microwave, and the whole network has circular polarization characteristics.

[0055] like Figure 4 As shown in the figure, the simulation results of the S-parameters of the millimeter-wave operating frequency band of the dual-frequency circularly polarized fusion antenna described in this embodiment are displayed. It can be seen from the figure that the range of reflection coefficient less than -10dB is 23.2GHz-27GHz.

[0056] like Figure 5 As shown in the figure, the simulation results of the axial ratio (AR) of the millimeter-wave operating frequency band of the dual-frequency circularly polarized fusion antenna described above in this embodiment are displayed. It can be seen from the figure that the range where AR is less than 3dB is 23.4GHz-27GHz, and the frequency band where S-parameters and axial ratio coincide is 23.4GHz-27GHz, which has circular polarization characteristics.

[0057] like Figure 6 and Figure 7 As shown, the simulation results of the XOZ and YOZ plane radiation patterns of the center frequency of the millimeter-wave operating frequency band of the dual-frequency circularly polarized fusion antenna described above in this embodiment are displayed. It can be seen from the figure that the maximum gain is 17.72dBi.

[0058] like Figure 8 As shown in the figure, the simulation results of the microwave operating frequency band S-parameters of the dual-frequency circularly polarized fusion antenna described above in this embodiment are displayed. It can be seen from the figure that the range of reflection coefficient less than -10dB is 1.552GHz-1.564GHz.

[0059] like Figure 9 As shown in the figure, the simulation results of the axial ratio (AR) of the microwave operating frequency band of the dual-frequency circularly polarized fusion antenna described above in this embodiment are displayed. It can be seen from the figure that the range where AR is less than 3dB is 1.554GHz-1.563GHz, and the frequency band where S-parameters and axial ratio coincide is 1.554GHz-1.563GHz, which has circular polarization characteristics.

[0060] like Figure 10 and Figure 11 As shown, the simulation results of the XOZ and YOZ plane radiation patterns of the microwave operating frequency point of the dual-frequency circularly polarized fusion antenna described above in this embodiment at 1.56 GHz are displayed. It can be seen from the figure that the maximum gain is 1.6 dBi.

[0061] The above embodiments are merely preferred embodiments of the present invention, but do not limit other embodiments of the present invention. Any changes made according to the structure and principles of the present invention are included within the protection scope of the present invention.

Claims

1. A dual-frequency circularly polarized fusion antenna with a high frequency ratio, characterized in that, The system includes a first dielectric substrate (1), a second dielectric substrate (2), a first metal radiator (71), a second metal radiator (72), a third metal radiator (73), and a fourth metal radiator (74); the first dielectric substrate (1) is stacked on top of the second dielectric substrate (2); a copper-clad layer is provided on the lower surface of the first dielectric substrate (1) as a metal ground plane (11); the first metal radiator (71), the second metal radiator (72), the third metal radiator (73), and the fourth metal radiator (74) are all disposed on the upper surface of the first dielectric substrate (1) and are distributed in a 90-degree rotational manner with the center of the upper surface of the first dielectric substrate (1) as the rotation axis; a microwave feed network (4), a first 180-degree phase difference power divider (31), a second 180-degree phase difference power divider (32), a third 180-degree phase difference power divider (33), and a fourth 180-degree phase difference power divider (34) are provided on the lower surface of the second dielectric substrate (2); the first metal radiator (71) passes through a first millimeter... A millimeter-wave metal probe (81) is connected to a first 180-degree phase difference power divider (31). A second metal radiator (72) is connected to a second 180-degree phase difference power divider (32) via a second millimeter-wave metal probe (82). A third metal radiator (73) is connected to a third 180-degree phase difference power divider (33) via a third millimeter-wave metal probe (83). A fourth metal radiator (74) is connected to a fourth 180-degree phase difference power divider (34) via a fourth millimeter-wave metal probe (84). A first metal radiator (71) is connected to a microwave feed network (4) via a first microwave metal probe (51). A second metal radiator (72) is connected to a microwave feed network (4) via a second microwave metal probe (52). A third metal radiator (73) is connected to a microwave feed network (4) via a third microwave metal probe (53). A fourth metal radiator (74) is connected to a microwave feed network (4) via a fourth microwave metal probe (54). The fourth metal radiator (74) includes a first rectangular metal patch (741), a second rectangular metal patch (742), and a first rectangular metal strip (12), a second rectangular metal strip (13), a third rectangular metal strip (14), and a fourth rectangular metal strip (15) located between the first rectangular metal patch (741) and the second rectangular metal patch (742). The first rectangular metal strip (12), the second rectangular metal strip (13), the third rectangular metal strip (14), and the fourth rectangular metal strip (15) are spaced apart along the length direction of the first rectangular metal patch (741) and the second rectangular metal patch (742). 742) The first rectangular metal strip (12), the second rectangular metal strip (13), the third rectangular metal strip (14), and the fourth rectangular metal strip (15) are connected together; the structure of the first metal radiator (71), the second metal radiator (72), and the third metal radiator (73) is the same as that of the fourth metal radiator (74), and the second metal radiator (72) is obtained by symmetry of the fourth metal radiator (74) about the center of the upper surface of the first dielectric plate (1); the first metal radiator (71) and the third metal radiator (73) are obtained by rotating the second metal radiator (72) and the fourth metal radiator (74) 90 degrees clockwise about the center of the upper surface of the first dielectric plate (1); The first metal radiator (71) is connected to the metal ground plane (11) through the first metal pillar group (61), the second metal radiator (72) is connected to the metal ground plane (11) through the second metal pillar group (62), the third metal radiator (73) is connected to the metal ground plane (11) through the third metal pillar group (63), and the fourth metal radiator (74) is connected to the metal ground plane (11) through the fourth metal pillar group (64), so as to ensure that the first metal radiator (71), the second metal radiator (72), the third metal radiator (73), and the fourth metal radiator (74) form a cascaded triangular cavity standing wave radiation in the millimeter wave frequency band, and work as a quarter-wavelength patch antenna with terminal short circuit in the microwave frequency band.

2. The dual-frequency circularly polarized fusion antenna with a large frequency ratio according to claim 1, characterized in that, The first 180-degree phase difference power divider (31), the second 180-degree phase difference power divider (32), the third 180-degree phase difference power divider (33), and the fourth 180-degree phase difference power divider (34) are all loaded with a high-pass filter (9); the first 180-degree phase difference power divider (31), the second 180-degree phase difference power divider (32), the third 180-degree phase difference power divider (33), and the fourth 180-degree phase difference power divider (34) all include a millimeter-wave input port (30), a first millimeter-wave output port (301), a second millimeter-wave output port (302), and a millimeter-wave 180-degree shift... The phase converter (303) and the millimeter-wave quarter-wave impedance transformer (304) are connected to the millimeter-wave quarter-wave impedance transformer (304) via transmission lines. The millimeter-wave quarter-wave impedance transformer (304) is connected to the millimeter-wave 180-degree phase shifter (303) and the high-pass filter (9) via transmission lines. The millimeter-wave 180-degree phase shifter (303) is connected to the high-pass filter (9) via transmission lines. The high-pass filter (9) is connected to the first millimeter-wave output port (301) and the second millimeter-wave output port (302) respectively.

3. A dual-frequency circularly polarized fusion antenna with a large frequency ratio according to claim 2, characterized in that, The microwave power supply network (4) includes a microwave input port (40), a first microwave output port (41), a second microwave output port (42), a third microwave output port (43), a fourth microwave output port (44), a microwave quarter-wavelength impedance transformer (45), a first 90-degree phase shifter (46), a second 90-degree phase shifter (47), and a microwave 180-degree phase shifter (48). The first microwave output port (41) is connected to the first microwave metal probe (51) to power the first metal radiator (71), the second microwave output port (42) is connected to the second microwave metal probe (52) to power the second metal radiator (72), and the third microwave output port (43) is connected to the third microwave metal probe (53) to power the third metal radiator (73). The fourth microwave output port (44) is connected to the fourth microwave metal probe (54) to feed the fourth metal radiator (74); the microwave input port (40) is connected to the microwave quarter-wavelength impedance transformer (45) through a transmission line; the microwave quarter-wavelength impedance transformer (45) is connected to the first microwave output port (41), the first 90-degree phase shifter (46) and the microwave 180-degree phase shifter (48) through a transmission line; the microwave 180-degree phase shifter (48) is connected to the third microwave output port (43) and the second 90-degree phase shifter (47) through a transmission line; the second microwave output port (42) is loaded on the first 90-degree phase shifter (46); and the fourth microwave output port (44) is loaded on the second 90-degree phase shifter (47).

4. A dual-frequency circularly polarized fusion antenna with a large frequency ratio according to claim 3, characterized in that, The first metal radiator (71), the second metal radiator (72), the third metal radiator (73), the fourth metal radiator (74), the microwave feed network (4), the first 180-degree phase difference power divider (31), the second 180-degree phase difference power divider (32), the third 180-degree phase difference power divider (33), and the fourth 180-degree phase difference power divider (34) are all copper-clad layers.

5. A dual-frequency circularly polarized fusion antenna with a large frequency ratio according to claim 4, characterized in that, The first microwave metal probe (51), the second microwave metal probe (52), the third microwave metal probe (53), the fourth microwave metal probe (54), the first metal column group (61), the second metal column group (62), the third metal column group (63), the fourth metal column group (64), the first millimeter wave metal probe (81), the second millimeter wave metal probe (82), the third millimeter wave metal probe (83), and the fourth millimeter wave metal probe (84) are all copper metal columns.

6. A dual-frequency circularly polarized fusion antenna with a large frequency ratio according to claim 5, characterized in that, When the microwave input port (40) of the microwave feed network (4) is excited, the dual-frequency circularly polarized fusion antenna operates in the microwave frequency band, and a single radiator is equivalent to a quarter-wavelength terminal short-circuit patch antenna; when the first 180-degree phase difference power divider (31) is excited with 0-degree phase, the second 180-degree phase difference power divider (32) is excited with 90-degree phase, the third 180-degree phase difference power divider (33) is excited with 180-degree phase, and the fourth 180-degree phase difference power divider (34) is excited with 270-degree phase, the dual-frequency circularly polarized fusion antenna operates in the millimeter-wave frequency band, and a single radiator is equivalent to a 2×7 cascaded triangular cavity array.

7. The design method of a dual-frequency circularly polarized fusion antenna with a large frequency ratio according to any one of claims 1 to 6, characterized in that, Includes the following steps: Select the microwave frequency f1 and the millimeter wave frequency f2 as the operating center frequencies; Calculate frequency ratio Determine the number of cascaded triangular cavities. Determine the number of rectangular metal strips. Therefore, the number of rectangular metal strips can be obtained from the frequency ratio: ; Determine the length of the rectangular metal patch Width W, Length Width W can be generated by We get the value where C0 is the speed of light in a vacuum. The dielectric constant of the dielectric substrate; Two rectangular metal patches are mirrored and connected with rectangular metal strips to obtain a metal radiator. The metal radiator is then symmetrical about the top surface of the first dielectric substrate. The two symmetrical metal radiators are then rotated 90 degrees clockwise about the top surface of the first dielectric substrate to obtain four metal radiators. A metal pillar assembly is loaded at one end of the metal radiator near the center of the first dielectric substrate, a millimeter-wave metal probe is loaded at the other end away from the center of the first dielectric substrate, and a microwave metal probe is loaded at the center of the rectangular metal strip near the center of the first dielectric substrate. The lower surface of the first dielectric substrate is coated with copper to serve as a metal ground plane that contacts the metal pillar assembly. A microwave feed network and four 180-degree phase difference power dividers are designed on the lower surface of the second dielectric substrate; the output ports of the microwave feed network have phase differences of 0 degrees, 90 degrees, 180 degrees, and 270 degrees, and are connected to microwave metal probes; each 180-degree phase difference power divider is loaded with a high-pass filter, and its output port is connected to a millimeter-wave metal probe. When four 180-degree phase difference power dividers are excited with phase characteristics of 0 degrees, 90 degrees, 180 degrees, and 270 degrees, a single radiator can operate in the millimeter-wave frequency band, and the radiation characteristics are those of a cascaded triangular cavity array with overall circular polarization characteristics. When the microwave feed network is excited, a single radiator can be equivalent to a patch of a quarter wavelength of microwave, and the whole network has circular polarization characteristics.

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