A three-frequency circularly polarized duplex antenna with isolated transmitting and receiving ports

Abstract

The present invention discloses a three-frequency circularly polarized duplex antenna with isolated transmitting and receiving ports, comprising a first dielectric layer (6), a second dielectric layer (7) and a third dielectric layer (8) arranged in sequence from top to bottom; an upper patch (1) is arranged on the upper surface of the first dielectric layer (6), a lower patch (2) is arranged on the upper surface of the second dielectric layer (7), a metal ground (3) is arranged on the upper surface of the third dielectric layer (8), and a triplexer circuit layer (5) is arranged on the lower surface of the third dielectric layer (8); the upper patch (1) is a square metal patch, and a rectangular groove perpendicular to the edge is opened on each side of the upper patch (1); the lower patch (2) is a square patch, and a rectangular groove is opened in the center of the lower patch (2), and a T-shaped groove is opened on each side. The present invention can achieve high isolation between the transmitting port and the receiving port.

Description

Technical Field

[0001] The invention belongs to the field of microwave devices, and specifically relates to a three-frequency circularly polarized duplex antenna with isolated transmitting and receiving ports. The antenna works at 1.615GHz left-hand circularly polarized transmitting, 1.268GHz right-hand circularly polarized receiving and 2.492GHz right-hand circularly polarized receiving, and the isolation between the transmitting and receiving ports is greater than 52dB. Background Art

[0002] Currently, advanced platforms are equipped with the Beidou navigation system (1.268GHz right-hand circular polarization reception) and the Beidou short message transceiver system (1.615GHz left-hand circular polarization for transmission and 2.492GHz right-hand circular polarization for reception). Usually, three separate antennas perform their respective functions, resulting in a large number of antennas on advanced platforms and difficult layout. Using a single antenna to cover the functions of the above three antennas to achieve antenna integration can improve the platform's integration and effectively alleviate the pressure on antenna layout on advanced platforms.

[0003] With the increase in transmitter power and receiver sensitivity, in order to ensure the RF self-compatibility of transmitters and receivers on the same platform, higher requirements are placed on the transmitter out-of-band suppression capability and isolation between antennas. The maximum Beidou short message transmission power can reach 40dBm, and the Beidou navigation reception sensitivity can reach -130dBm. Even considering that the navigation receiver itself has an anti-interference capability of 20dB and the transmitter out-of-band suppression reaches a high 100dBc, a high isolation of more than 50dB still needs to be ensured between antennas. Summary of the invention

[0004] The purpose of the present invention is to overcome the deficiencies of the prior art and provide a three-frequency circularly polarized duplex antenna with isolated transmitting and receiving ports, which can achieve high isolation between the transmitting port and the receiving port.

[0005] The object of the present invention is achieved through the following technical solutions: A three-frequency circularly polarized duplex antenna with isolated transmitting and receiving ports, comprising a first dielectric layer, a second dielectric layer and a third dielectric layer arranged in sequence from top to bottom;

[0006] An upper patch is disposed on the upper surface of the first dielectric layer, a lower patch is disposed on the upper surface of the second dielectric layer, a metal ground is disposed on the upper surface of the third dielectric layer, and a triplexer circuit layer is disposed on the lower surface of the third dielectric layer;

[0007] The upper patch is a square metal patch, and each side of the upper patch is provided with a rectangular groove perpendicular to the side;

[0008] The lower patch is a square patch, a rectangular groove is opened in the center of the lower patch, and a T-shaped groove is opened on each side;

[0009] The lower patch is provided with a first circular groove, the metal ground is provided with a second circular groove, and the first circular groove and the second circular groove are aligned vertically;

[0010] The triple-frequency circularly polarized duplex antenna also includes a short-circuit probe, one end of which is connected to the upper patch, and the other end of which passes through the first dielectric layer, the first circular groove of the lower patch, the second dielectric layer, the second circular groove on the metal ground, and the third dielectric layer in sequence to be connected to the triplexer circuit layer.

[0011] The first circular groove and the second circular groove are provided so that the short-circuit probe does not contact the lower patch and the metal ground when passing through.

[0012] The triplexer circuit layer comprises a common connector and three channels; the common connector is connected to a short-circuit probe;

[0013] The first channel includes a port one, a first connecting arm, a first step impedance resonator and three open rings, wherein the port one is connected to a common joint through the first connecting arm; the three open rings are located on the same side of the first connecting arm; the first step impedance resonator passes through the first connecting arm;

[0014] The second channel includes a second port, a second connecting arm, a second ladder impedance resonator and two third ladder impedance resonators, wherein the second port is connected to a common joint through the second connecting arm, and the second ladder impedance resonator and each third ladder impedance resonator pass through the second connecting arm;

[0015] The third channel includes a port three, a third connecting arm, a fourth-step impedance resonator and a fifth-step impedance resonator, wherein the port three is connected to the common joint through the third connecting arm, and the fourth-step impedance resonator and the fifth-step impedance resonator both pass through the third connecting arm;

[0016] In each channel, the equivalent open-circuit frequency of the stepped impedance resonator is the operating frequency of the channel, the equivalent short-circuit frequency is the operating frequency of other channels, and the distance from the common joint is approximately one-quarter of the wavelength of its corresponding short-circuit frequency.

[0017] The beneficial effects of the present invention are as follows: 1. The duplex antenna of the present invention realizes one left-hand circular polarization and two right-hand circular polarization working frequency bands simultaneously through the perturbation technology of stacking patches and slotting the patches.

[0018] 2. The duplex antenna of the present invention uses a short-circuit probe to directly connect the radiating patch and the microstrip triplexer, avoiding the need for additional cables and matching networks.

[0019] 3. The duplex antenna of the present invention realizes port isolation greater than 52dB between the transmitting port and the two receiving ports. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 is a side view of the duplex antenna of the present invention;

[0021] Figure 2 It is a schematic diagram of the upper patch of the duplex antenna of the present invention;

[0022] Figure 3 It is a schematic diagram of the lower patch of the duplex antenna of the present invention;

[0023] Figure 4 A schematic diagram of a duplex antenna triplexer of the present invention;

[0024] Figure 5 It is a schematic diagram of dimension marking of the stepped impedance resonator of the duplex antenna of the present invention;

[0025] Figure 6 is the reflection coefficient and axial ratio of the duplex antenna port 1 of the present invention;

[0026] Figure 7 is the reflection coefficient and axial ratio of the duplex antenna port 2 of the present invention;

[0027] Figure 8 is the reflection coefficient and axial ratio of the duplex antenna port 3 of the present invention;

[0028] Fig. 9 is the transmission coefficient of port 1 and port 2 of the duplex antenna of the present invention;

[0029] Fig.10 is the transmission coefficient of port 2 and port 3 of the duplex antenna of the present invention. DETAILED DESCRIPTION

[0030] The technical solution of the present invention is further described in detail below in conjunction with the accompanying drawings, but the protection scope of the present invention is not limited to the following.

[0031] The present invention can work simultaneously in 1.615GHz left-hand circular polarization transmission, 1.268GHz right-hand circular polarization reception and 2.492GHz right-hand circular polarization reception, and is composed of two radiating patches and a microstrip triplexer. Two rectangular radiating patches are stacked to realize triple frequencies, four rectangular slots are opened around the upper rectangular patch to realize left-hand circular polarization, four T-shaped slots are opened around the lower rectangular patch, and a rectangular slot is opened in the middle to realize dual-frequency right-hand circular polarization, the microstrip triplexer is composed of a ladder impedance resonator and an open ring resonator, the upper patch is directly cascaded with the microstrip triplexer through a short-circuit probe, and the lower patch is excited by the electromagnetic coupling of the upper patch.

[0032] like Figure 1 As shown, a three-frequency circularly polarized duplex antenna with isolated transmitting and receiving ports comprises a first dielectric layer 6, a second dielectric layer 7 and a third dielectric layer 8 arranged in sequence from top to bottom;

[0033] An upper patch 1 is disposed on the upper surface of the first dielectric layer 6, a lower patch 2 is disposed on the upper surface of the second dielectric layer 7, a metal ground 3 is disposed on the upper surface of the third dielectric layer 8, and a triplexer circuit layer 5 is disposed on the lower surface of the third dielectric layer 8;

[0034] like Figure 2 The upper patch 1 is a square metal patch, and each side of the upper patch 1 is provided with a rectangular groove perpendicular to the side, and the sizes of the rectangular grooves on opposite sides are the same;

[0035] like Figure 3 As shown, the lower patch 2 is a square patch, a rectangular slot is provided at the center of the lower patch 2, and a T-shaped slot is provided on each side; dual-frequency circular polarization is achieved through the combination of multiple slots;

[0036] The lower patch 2 is provided with a first circular groove, and the metal ground 3 is provided with a second circular groove, and the first circular groove and the second circular groove are aligned vertically;

[0037] The triple-frequency circularly polarized duplex antenna also includes a short-circuit probe 4, one end of which is connected to the upper patch 1, and the other end of the short-circuit probe passes through the first dielectric layer 6, the first circular groove of the lower patch 2, the second dielectric layer 4, the second circular groove on the metal ground 3, and the third dielectric layer 8 in sequence to be connected to the triplexer circuit layer 5.

[0038] The triplexer circuit layer is as follows Figure 4 As shown, the triplexer circuit layer 5 includes a common connector and three channels;

[0039] The first channel includes a port one (port 1), a first connecting arm, a first step impedance resonator (resonator 1) and three open rings, wherein the port one is connected to a common joint through the first connecting arm; the three open rings are located on the same side of the first connecting arm; the first step impedance resonator passes through the first connecting arm;

[0040] The first connecting arm includes a first connecting branch, a second connecting branch, a first open ring matching branch and a second open ring matching branch; one end of the first connecting branch is connected to the common joint, and the other end is connected to the first end of the first open ring matching branch, and the first step impedance resonator (resonator 1) passes through the first connecting branch; one end of the second connecting branch is connected to port 1 (port 1), and the other end of the second connecting branch is connected to the first end of the second open ring matching branch; the first open ring matching branch and the second open ring matching branch are directly opposite, and a branch opening is provided between the first open ring matching branch and the second open ring matching branch; the width of the first open ring matching branch and the second open ring matching branch is smaller than the width of the first connecting branch and the second connecting branch; the sizes of the three open rings are exactly the same, wherein the first open ring is located on the upper side of the first open ring matching branch, and the opening is to the right; the second open ring is located on the second open ring matching branch, and the opening is to the left; the third open ring is located on the upper side of the first open ring and the second open ring, and the opening is directly opposite to the branch opening between the first open ring matching branch and the second open ring matching branch.

[0041] The second channel includes a second port (port 2), a second connecting arm, a second ladder impedance resonator (resonator 2) and two third-step impedance resonators (resonator 3), wherein the second port is connected to a common joint through the second connecting arm, and the second ladder impedance resonator and each third-step impedance resonator pass through the second connecting arm;

[0042] The third channel includes port three (port 3), a third connecting arm, a fourth-step impedance resonator (resonator 4) and a fifth-step impedance resonator (resonator 5), wherein the port three is connected to the common joint through the third connecting arm, and the fourth-step impedance resonator and the fifth-step impedance resonator both pass through the third connecting arm;

[0043] In each channel, the equivalent open-circuit frequency of the stepped impedance resonator is the operating frequency of the channel, and the equivalent short-circuit frequency is the operating frequency of other channels. Specifically:

[0044] The three open rings in the first channel are regarded as equivalent resonators; the equivalent short-circuit frequency of the first-step impedance resonator is the operating frequency of the third channel, and the short-circuit frequency of the equivalent resonator is the operating frequency of the second channel; the equivalent short-circuit frequency of the second-step impedance resonator is the operating frequency of the third channel, and the equivalent short-circuit frequency of the third-step impedance resonator is the operating frequency of the first channel; the equivalent short-circuit frequency of the fourth-step impedance resonator is the operating frequency of the second channel; the equivalent short-circuit frequency of the fifth-step impedance resonator is the operating frequency of the first channel;

[0045] The distance between each step impedance resonator and the common joint is approximately one-quarter wavelength of its corresponding short-circuit frequency; among them, there are two third-step impedance resonators, and it is only necessary to satisfy that the distance between the third-step impedance resonator closest to the common joint and the common joint is approximately one-quarter wavelength of its corresponding short-circuit frequency.

[0046] By reasonably designing the stepped impedance resonator and selecting the spacing, port isolation greater than 52dB is achieved. The following is a detailed description of the above-mentioned three-frequency circularly polarized duplex antenna with a transmitting and receiving port isolation greater than 52dB provided by the present invention through a specific embodiment.

[0047] Embodiment 1:

[0048] First, a three-frequency circularly polarized duplex antenna with a transmit and receive port isolation greater than 52dB is given corresponding specific size values ​​and relative position parameter values, and further a performance test is performed on a three-frequency circularly polarized duplex antenna with a transmit and receive port isolation greater than 52dB of the present invention. It should be understood that those skilled in the art can adjust the operating frequency of the antenna by adjusting the patch size without significantly changing the antenna structure to adapt to different application scenarios of the antenna.

[0049] In this embodiment, the dimensions of the relevant parameters of a triple-frequency circularly polarized duplex antenna with a transmit and receive port isolation greater than 52 dB are as follows (unit: mm):

[0050]

[0051]

[0052] See also Figure 2-Figure 5 , where lp 1 is the side length of the upper patch; lc 1 and wc 1 lc are the length and width of the upper and lower rectangular grooves of the upper patch respectively; 2 and wc 2 lp are the length and width of the left and right rectangular slots of the upper patch respectively; 2 is the side length of the lower patch; lc 3 and wc 3 are the length and width of the rectangular slot in the center of the lower patch; lc 4 and wc 4 lc are the length and width of the outer part of the left side and the upper and lower T-slots respectively; 5 and wc 5 are the length and width of the inner part of the T-slot respectively; lc 6 The width of the outer part of the right T-slot; l 1 is the distance from the common connector of the triplexer to resonator 1; l 2-1 , l2-2 , l 2-3 is the distance between resonator 1 and the split ring resonator; l 3 is the distance from the common connector of the triplexer to the resonator 2; l 4 is the smaller distance between resonator 2 and resonator 3; l 5 is the distance from the common connector of the triplexer to the resonator 4; l 6 is the distance between resonator 4 and resonator 5; l 7 is the distance from the open ring to port 1; l 8 is the distance between the two resonators 3; l 9 is the distance from resonator 3 to port 2; l 10 is the distance from resonator 5 to port 3; the corresponding parts of each resonator size are as follows Figure 5 As shown, Figure 5 The i in the figure is replaced by the resonator number; lo 1 and lo 2 are the length and width of the overall structure of the open ring respectively; 1 is the width of the copper-covered part of the open ring; s 1 、s 2 、s 3 、s 4 are the spacing between the parts of the open ring; 2 is the width of the coupling feed section below the split ring.

[0053] The first dielectric layer is 0.8 mm thick and made of Fr4. Its relative dielectric constant and loss tangent are 4.4 and 0.02 respectively. The upper patch responsible for generating 1.615 GHz left-hand circularly polarized radiation is printed on it. Its structure is as follows: Figure 2 As shown; the second layer of medium is Fr4 with a thickness of 1.2mm, on which is printed the lower layer patch responsible for generating 1.268GHz and 2.492GHz right-hand circularly polarized radiation, and its structure is as follows Figure 3 As shown; the third dielectric layer at the bottom has a thickness of 1.524 mm and is made of F4B450. Its corresponding dielectric constant and loss tangent are 4.5 and 0.0015 respectively. The upper surface is printed with a metal ground and the lower surface is printed with the proposed triplexer.

[0054] See also Figure 6-Figure 10 , the antenna performance of the present invention is plotted based on the above specific parameter values.

[0055] See also Figure 6 , are the reflection coefficient and axial ratio of the antenna port 1 of the present invention. The reflection coefficient in its operating frequency band is less than -10dB, and the axial ratio of left-hand circular polarization working at 1.615GHz is 1.2dB.

[0056] See also Figure 7, which are the reflection coefficient and axial ratio of antenna port 2 of the present invention. The reflection coefficient within its operating frequency band is less than -10 dB, and the right-hand circular polarization axial ratio is 1.8 dB.

[0057] See Figure 8 , which are the reflection coefficient and axial ratio of antenna port 3 of the present invention. The reflection coefficient within its operating frequency band is less than -10 dB, and the right-hand circular polarization axial ratio is 1.3 dB.

[0058] In the embodiment of the present application, port 2 is the transmitting port, and the transmitting frequency is 1.615 GHz. Ports 1 and 3 are receiving ports. See Fig. 9 , which is the transmission coefficient of antenna ports 1 and 2 of the present invention at the receiving frequency of 1.268 GHz, and the isolation degree is greater than 52 dB. See Fig.10 , which is the transmission coefficient of antenna ports 2 and 3 of the present invention at the receiving frequency of 2.492 GHz, and the isolation degree is greater than 55 dB.

[0059] The above-described embodiments are only the preferred embodiments of the present invention, and do not impose any form of limitation on the present invention. Any person skilled in the art, without departing from the scope of the technical solution of the present invention, may make more possible changes, modifications, or retouches to the technical solution of the present invention by using the disclosed technical content, or such modifications are equivalent embodiments of the present invention. Therefore, all equivalent changes made according to the idea of the present invention without departing from the content of the technical solution of the present invention shall be covered by the protection scope of the present invention.

Claims

1. A three-frequency circularly polarized duplex antenna with isolated transmit and receive ports, characterized in that: It comprises a first dielectric layer (6), a second dielectric layer (7) and a third dielectric layer (8) which are arranged in sequence from top to bottom; An upper patch (1) is arranged on the upper surface of the first dielectric layer (6), a lower patch (2) is arranged on the upper surface of the second dielectric layer (7), a metal ground (3) is arranged on the upper surface of the third dielectric layer (8), and a triplexer circuit layer (5) is arranged on the lower surface of the third dielectric layer (8); The upper patch (1) is a square metal patch, and each side of the upper patch (1) is provided with a rectangular groove perpendicular to the side; The lower patch (2) is a square patch, a rectangular groove is provided at the center of the lower patch (2), and a T-shaped groove is provided on each side; The lower patch (2) is provided with a first circular groove, and the metal ground (3) is provided with a second circular groove, and the first circular groove and the second circular groove are aligned vertically; The triple-frequency circularly polarized duplex antenna further comprises a short-circuit probe (4), one end of which is connected to the upper patch (1), and the other end of which sequentially passes through the first dielectric layer (6), the first circular groove of the lower patch (2), the second dielectric layer (7), the second circular groove on the metal ground (3), and the third dielectric layer (8) to be connected to the triplexer circuit layer (5).

2. The triple-frequency circularly polarized duplex antenna with isolated transmitting and receiving ports according to claim 1, characterized in that: The first dielectric layer (6), the second dielectric layer (7) and the third dielectric layer (8) all adopt dielectric substrates.

3. The triple-frequency circularly polarized duplex antenna with isolated transmitting and receiving ports according to claim 1, characterized in that: In the upper patch (1), the rectangular grooves opened on two opposite sides have the same size and are symmetrical to each other.

4. The triple-frequency circularly polarized duplex antenna with isolated transmitting and receiving ports according to claim 1, characterized in that: In the lower layer patch (2), except for the T-shaped groove on the right side, the other three T-shaped grooves have the same size.

5. The triple-frequency circularly polarized duplex antenna with isolated transmitting and receiving ports according to claim 1, characterized in that: The triplexer circuit layer (5) comprises a common connector and three channels, and the common connector is connected to a short-circuit probe (4); The first channel includes a port one, a first connecting arm, a first step impedance resonator and three open rings, wherein the port one is connected to a common joint through the first connecting arm; the three open rings are located on the same side of the first connecting arm; the first step impedance resonator passes through the first connecting arm; The second channel includes a second port, a second connecting arm, a second ladder impedance resonator and two third ladder impedance resonators, wherein the second port is connected to a common joint through the second connecting arm, and the second ladder impedance resonator and each third ladder impedance resonator pass through the second connecting arm; The third channel includes a port three, a third connecting arm, a fourth-step impedance resonator and a fifth-step impedance resonator, wherein the port three is connected to the common joint through the third connecting arm, and the fourth-step impedance resonator and the fifth-step impedance resonator both pass through the third connecting arm; In each channel, the equivalent open-circuit frequency of the stepped impedance resonator is the operating frequency of the channel; In each channel, the equivalent short-circuit frequency of the ladder impedance resonator is the operating frequency of other channels: the three open rings in the first channel are regarded as equivalent resonators; the equivalent short-circuit frequency of the first ladder impedance resonator is the operating frequency of the third channel, and the short-circuit frequency of the equivalent resonator is the operating frequency of the second channel; the equivalent short-circuit frequency of the second ladder impedance resonator is the operating frequency of the third channel, and the equivalent short-circuit frequency of the third ladder impedance resonator is the operating frequency of the first channel; the equivalent short-circuit frequency of the fourth ladder impedance resonator is the operating frequency of the second channel; The equivalent short-circuit frequency of the fifth-step impedance resonator is the operating frequency of the first channel; The distance between each step impedance resonator and the common joint is one quarter of the wavelength of its corresponding short-circuit frequency; among them, there are two third step impedance resonators, and it is only necessary to satisfy that the distance between the third step impedance resonator closest to the common joint and the common joint is one quarter of the wavelength of its corresponding short-circuit frequency.

6. The triple-frequency circularly polarized duplex antenna with isolated transmitting and receiving ports according to claim 1, characterized in that: The upper patch (1) is arranged on the upper surface of the first dielectric layer (6) in a printed manner, and the lower patch (2) is arranged on the upper surface of the second dielectric layer (7) in a printed manner.

7. The triple-frequency circularly polarized duplex antenna with isolated transmitting and receiving ports according to claim 1, characterized in that: The metal ground (3) is arranged on the upper surface of the third dielectric layer (8) in a printed manner, and the triplexer circuit layer (5) is arranged on the lower surface of the third dielectric layer (8) in a printed manner.

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