A patch antenna for unit frequency scanning and subarray common aperture

Abstract

The application discloses a patch antenna for unit frequency scanning and subarray common aperture, which inlays H-shaped patches and square patches into coplanar common aperture with the assistance of parallel grooves, rectangular grooves, horizontal short grooves and rectangular notches, utilizes the influence of the parallel grooves and the rectangular grooves on the current distribution of two low-frequency modes, combines the isolation enhancement effect of the horizontal short grooves and the rectangular notches on the low-frequency and the high-frequency, realizes the patch antenna for unit frequency scanning and subarray common aperture, and has the advantages of similar working frequency and high gain, and simultaneously considers the simple structure, low profile and convenient integration.

Description

Technical Field

[0001] This invention relates to a microwave communication device, specifically to a patch antenna. Background Technology

[0002] Common-aperture patch antennas can integrate multiple patch antennas operating at different frequency bands within the same radiating aperture, offering advantages such as high space utilization, low profile, simple structure, and ease of integration. When a common-aperture patch antenna incorporates single-patch frequency scanning functionality, it can achieve rapid beam scanning without complex phase control circuitry, which is beneficial for improving the data transmission rate and anti-interference capability of communication systems, while also possessing the advantages of simple structure, low cost, and ease of implementation. When a common-aperture patch antenna includes an array, it helps to improve gain and increase coverage distance. Patch antennas designed for both single-element frequency scanning and subarray common-aperture configurations can combine the above advantages and characteristics, possessing significant development value and engineering significance.

[0003] Existing common-aperture patch antennas with beam scanning capabilities are mainly based on phased arrays or a combination of phased arrays and fixed-beam antennas. Compared to common-aperture patch antennas oriented towards single-element frequency scanning, they require complex phase control circuits, large dimensions, and complex structures. Other common-aperture patch antennas without beam scanning capabilities are classified according to the number of patch layers occupied by the common-aperture form into coplanar common-aperture patch antennas and multi-layer common-aperture patch antennas. Multi-layer common-aperture patch antennas cannot place radiators of multiple frequency bands in a single layer, thus exhibiting problems such as high profile, complex structure, and difficulty in integration. Coplanar common-aperture patch antennas have the advantages of low profile, simple structure, and easy integration, but currently there are no solutions or design methods for single-element frequency scanning and subarray common-aperture. Therefore, combining the advantages of coplanar common-aperture patch antennas with the requirement for single-element frequency scanning and subarray common-aperture, it is necessary to study and implement a solution for coplanar common-aperture patch antennas oriented towards single-element frequency scanning and subarray. Summary of the Invention

[0004] Purpose of the invention: In view of the above-mentioned prior art, a patch antenna for unit frequency scanning and subarray common aperture is proposed, which can realize unit frequency scanning and subarray side firing simultaneously, while operating at close frequencies and having similar high gain performance, and can also take into account simple structure, low profile and easy integration.

[0005] Technical solution: A patch antenna for unit frequency scanning and subarray common aperture, comprising a top patch, a bottom metal structure, an intermediate dielectric substrate, and several metallized vias; The top-layer patch includes an H-shaped patch with embedded parallel grooves and two square patches; wherein, the parallel grooves are symmetrically distributed on both sides of the center of the H-shaped patch; in the two symmetrical rectangular grooves of the H-shaped patch, there are horizontally extending short grooves at the two bottom corners of each groove; the two square patches are respectively located in the two symmetrical rectangular grooves of the H-shaped patch, with gaps left between them and the edges of the grooves; a rectangular notch is provided at the center of each of the left and right sides of the square patch; The bottom metal structure is a rectangular metal ground; three coaxial probes are inserted from the bottom surface of the bottom metal structure upwards and are respectively connected to the H-shaped patch and the two square patches; When a low-frequency signal is fed in through one of the coaxial probes connected to the H-shaped patch, and a high-frequency signal is fed in through the other two coaxial probes connected to the two square patches respectively, the low-frequency unit frequency sweep and the high-frequency subarray side-emitting function are realized. When the coaxial probes connecting the two square patches are excited in opposite phase, the high-frequency subarray is realized and the vertically polarized subarray side-radiation is obtained.

[0006] Furthermore, the length of the H-shaped patch is 0.97λ. 01 -1.07λ 01 Between, with a width of 0.86λ 01 -0.96λ 01 Between, λ 01 The free-space wavelength corresponds to the center frequency of the low-frequency patch antenna; the side length of the square patch is 0.285λ. 02 -0.395λ 02 Between, λ 02 The free-space wavelength corresponds to the center frequency of the high-frequency patch antenna; the slot spacing of the parallel slots is 0.05λ. 01 -0.14λ 01 Between, the groove length is 0.15λ 01 -0.45λ 01 Between; the length of the short groove is between 0.01λ. 01 -0.06λ 01 between.

[0007] Furthermore, it also includes three metallized vias that pass vertically through the top layer patch, the middle layer dielectric substrate, and the bottom layer metal structure. One of the metallized vias is located on the horizontal symmetry line of the antenna structure, and the other two metallized vias are symmetrically distributed on the vertical symmetry line. The top ends of the three metallized vias are respectively connected to the H-shaped patch and two square patches. Three circular grooves are provided on the rectangular metal ground, and the ends of each metallized via are located in the center of the circular grooves. The inner conductors of the three coaxial probes are inserted into the metallized vias and connected to the H-shaped patch and the square patches respectively. The outer conductors of the coaxial probes are connected to the rectangular metal ground.

[0008] Beneficial Effects: Existing common-aperture patch antennas suffer from limitations in simultaneously achieving element frequency sweep functionality, low profile, low structural complexity, and high integration. This invention embeds H-shaped and square patches in a coplanar, common-aperture configuration using parallel slots, rectangular grooves, horizontal short slots, and rectangular notches. Utilizing the influence of parallel slots and rectangular grooves on the current distribution of the two low-frequency modes, combined with the isolation enhancement effect of horizontal short slots and rectangular notches between low and high frequencies, this invention achieves a common-aperture patch antenna oriented towards element frequency sweep and subarrays. It offers advantages such as similar operating frequencies and high gain, while also maintaining a simple structure, low profile, and ease of integration.

[0009] Specifically, the large-diameter H-shaped patch contains symmetrical parallel slots, symmetrical rectangular grooves, and short horizontal slots at the bottom corners. The parallel slots and rectangular grooves are used to form two low-frequency modes, with horizontally unidirectional and horizontally reversed current trends, respectively, enabling low-frequency operation that supports high-gain unit frequency sweeps. The short horizontal slots at the bottom corners are used to adjust the current distribution near the square patches, thereby enhancing the isolation between low-frequency and high-frequency operation. Two square patches with rectangular notches at their centers are located within the upper and lower rectangular grooves of the H-shaped patch. Under the excitation of the inverting probe, they enable high-frequency segment array operation and can generate horizontal current to enhance low-frequency gain during low-frequency operation. The rectangular notches are used to adjust the vertical current distribution near the square patches, thereby improving the isolation between low-frequency and high-frequency operation. Attached Figure Description

[0010] Figure 1 This is a schematic cross-sectional view of the antenna structure of the present invention; Figure 2 This is a top view of the antenna structure of the present invention; Figure 3 This is a schematic diagram of the underlying metal structure of the antenna of the present invention; Figure 4 The simulation curves for antenna matching, isolation, and gain of the present invention are shown, where (a) is the low-frequency antenna and (b) is the high-frequency antenna. Figure 5 The diagram shows the radiation patterns of the antenna of the present invention at two frequency points in the low-frequency band, where (a) is the radiation pattern at 2.97 GHz. E Surface radiation pattern, (b) is at 2.97 GHz. H Surface radiation pattern, (c) is at 3.08 GHz. E Surface radiation pattern, (d) is at 3.08 GHz. H Surface radiation pattern; Figure 6 The antenna of this invention operates at a high frequency (3.38 GHz). E Face to face H Surface radiation pattern, where (a) is E(b) is H noodle. Detailed Implementation

[0011] The invention will now be further explained with reference to the accompanying drawings.

[0012] like Figure 1 As shown, a patch antenna for unit frequency scanning and subarray co-aperture consists of a top patch 1, a bottom metal structure 2, an intermediate dielectric substrate 3, metallized vias 4, and a coaxial probe 5.

[0013] like Figure 2 As shown, the top layer patch 1 consists of an H-shaped patch 1-1 with an embedded parallel groove 1-3 and two square patches 1-2. The parallel groove 1-3 is symmetrically distributed on both sides of the center of the H-shaped patch 1-1. Within the two symmetrical rectangular grooves on the top and bottom of the H-shaped patch, there are horizontally extending short grooves 1-4 at the two bottom corners of each groove. The two square patches 1-2 are located within the two symmetrical rectangular grooves on the top and bottom of the H-shaped patch 1-1, with gaps between them and the edges of the grooves. A rectangular notch 1-5 is provided at the center of each of the left and right sides of the square patches 1-2.

[0014] The length of H-type patch 1-1 (in the X-axis direction of the figure) is 0.97λ. 01 -1.07λ 01 Between these values, the width (in the Y-axis direction of the figure) is between 0.86λ. 01 -0.96λ 01 Between, λ 01 The free-space wavelength corresponds to the center frequency of the low-frequency patch antenna; the side length of square patch 1-2 is 0.285λ. 02 -0.395λ 02 Between, λ 02 This represents the free-space wavelength corresponding to the center frequency of the high-frequency patch antenna. The slot spacing of parallel slots 1-3 is 0.05λ. 01 -0.14λ 01 Between, the groove length is 0.15λ 01 -0.45λ 01 Between. The lengths of short slots 1-4 are between 0.01λ. 01 -0.06λ 01 between.

[0015] like Figure 3 As shown, the bottom metal structure 2 is a rectangular metal ground located on the lower surface of the intermediate dielectric substrate 3, and is etched with three small circular grooves 2-1.

[0016] There are three metallized vias 4, which pass vertically through the top layer patch 1, the intermediate layer dielectric substrate 3, and the bottom layer metal structure 2, respectively. The end of each metallized via 4 is located at the center of a small circular groove 2-1. One metallized via 4 is located on the horizontal line of symmetry of the structure, and the other two metallized vias 4 are symmetrically distributed on the vertical line of symmetry. The tops of the three metallized vias 4 are connected to the H-type patch 1-1 and the two square patches 1-2, respectively. The inner conductors of the three coaxial probes 5 are inserted into the metallized vias 4 and connected to the H-type patch 1-1 and the square patches 1-2, respectively. The outer conductors of the coaxial probes 5 are connected to the rectangular metal ground.

[0017] For the proposed patch antenna oriented towards unit frequency scanning and subarray common aperture, low-frequency signals are fed in through coaxial probes on the horizontal symmetry line, and high-frequency signals are fed in through two coaxial probes on the vertical symmetry line. Under the action of the overall structure, the low-frequency unit frequency scanning and high-frequency subarray side firing functions are realized.

[0018] During this process, the top-layer patch, under the influence of parallel slots 1-3 and the upper and lower rectangular grooves of the H-type patch 1-1, is excited by a coaxial probe located on a horizontal line of symmetry, forming two large-aperture modes operating at low frequencies. Mode 1 operates at a lower frequency, with strong horizontal currents in the same direction on both sides of the H-type patch 1-1. Due to the presence of the upper and lower rectangular grooves of the H-type patch 1-1, there is a slightly lower amplitude current on the inner square patch 1-2, which is in the same direction as the currents on both sides of the H-type patch 1-1. At the same time, due to the effect of parallel slots 1-3, the reverse current in the middle region is compressed into a smaller area, with a lower amplitude than the currents on both sides. Therefore, the overall current exhibits a horizontal and unidirectional trend. Combined with the large-aperture characteristics, high-gain radiation close to the normal direction is obtained.

[0019] Mode 2 operates at a slightly higher frequency than Mode 1. Strong horizontal reverse currents are present on both sides of the H-shaped patch 1-1, with the current amplitude on the right side greater than that on the left. Due to the presence of the upper and lower rectangular grooves of the H-shaped patch 1-1, a horizontal current component still exists on the inner square patch 1-2. Simultaneously, due to the effect of the parallel slot 1-3, a symmetrical vertical reverse current is observed in the small region between the parallel slots 1-3. Because the reverse vertical current contributes nothing to horizontal radiation, the overall current exhibits a horizontal reverse trend. Combined with the amplitude distribution and the large aperture characteristics, high-gain radiation far from the normal direction is achieved. The combination of Mode 1 and Mode 2 forms a low-frequency operating band, enabling a high-gain unit frequency sweep function.

[0020] When the top layer patch is excited in opposite phase by two coaxial probes on the vertical symmetry line, a high-frequency operating band is formed. The vertical current is mainly distributed on the two square patches 1-2 in the vertical direction. Each patch corresponds to a typical TM10 mode. Therefore, after arraying, high-gain vertical polarization subarray side radiation can be obtained.

[0021] The horizontally extending short slot 1-4 on the H-type patch 1-1 and the rectangular notch 1-5 on the square patch 1-2 are both used to adjust the current distribution near the square patch 1-2, which can reduce the coupling between the H-type patch 1-1 and the square patch array, thereby effectively enhancing the isolation between low-frequency and high-frequency operation.

[0022] In this embodiment, the dielectric substrate has a relative permittivity of 2.2, and the common-aperture radiator electrical dimension of the antenna is only 0.91λ. 01 ×1.02λ 01 ×0.016λ 01 The simulation results for the matching, isolation, and gain of the common-aperture antenna in this embodiment are as follows: Figure 4 As shown. The frequency ratio of the two operating frequency bands of the antenna is approximately 1.1. The low-frequency operating band covers 2.94 ~ 3.12 GHz, has two reflection nulls, a relative bandwidth of 5.9%, and a maximum gain of 12.2 dBi within the operating band. Figure 4 As shown in (a). The high-frequency operating band covers 3.34 ~ 3.41 GHz, with a relative bandwidth of 2.1%, and a maximum gain of 10.6 dBi within the operating band, as... Figure 4 As shown in (b), the isolation between the low-frequency port and the high-frequency port is greater than 20 dB.

[0023] Figure 5 The antenna's performance at low frequencies of 2.97 GHz and 3.08 GHz is given. E Face to face H Surface radiation pattern. At 2.97 GHz, the antenna's... E The surface radiation direction is -8°. H The 3-dB beamwidth of the plane is 46.5°, as shown below. Figure 5 As shown in (a) and (b), E Face to face H The cross-polarization level of the antenna is low. At 3.08 GHz, the antenna's... E The surface radiation direction is -25°. H The 3-dB beamwidth of the plane is 42.8°, as shown below. Figure 5 As shown in (c) and (d), E Face to face H The cross-polarization level of the surface is low. (Overall) Figure 4 and Figure 5 It can be seen that this common-aperture antenna achieves [performance] in the low-frequency operating band. E It features area frequency scanning and has high gain.

[0024] Figure 6 Figures (a) and (b) show the antenna at 3.38 GHz. E Face to face HThe radiation pattern shows that the antenna's radiation is lateral. E Face to face H The 3-dB beamwidths of the planes are 29° and 68°, respectively. E Face to face H The cross-polarization level of the surface is low. (Overall) Figure 4 and Figure 6 This common-aperture antenna achieves side-firing subarray radiation in the high-frequency operating band, with a gain comparable to that of the low-frequency antenna, and good isolation between low-frequency and high-frequency operation.

[0025] In summary, compared with the prior art, the present invention can realize a common aperture patch antenna for unit frequency scanning and subarrays, with high gain at similar operating frequencies, and also features simple structure, low profile and easy integration.

[0026] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A patch antenna for element frequency scanning and subarray common aperture, characterized in that, It includes a top layer patch (1), a bottom layer metal structure (2), an intermediate layer dielectric substrate (3), three metallized vias (4) and three coaxial probes (5); The top-layer patch (1) includes an H-shaped patch (1-1) with an embedded parallel slot (1-3) and two square patches (1-2); wherein, the parallel slot (1-3) is symmetrically distributed on both sides of the center of the H-shaped patch (1-1), and is used to excite two low-frequency resonant modes together with the two rectangular grooves symmetrically arranged on the top and bottom of the H-shaped patch (1-1); in the two rectangular grooves symmetrically arranged on the top and bottom of the H-shaped patch, there are horizontally extending short slots (1-4) at the two bottom corners of each groove, which are used to adjust the current distribution near the groove; the two square patches (1-2) are respectively located in the two rectangular grooves symmetrically arranged on the top and bottom of the H-shaped patch (1-1), and there is a gap between them and the edge of the groove; a rectangular notch (1-5) is provided at the center of the left and right sides of the square patch (1-2), which is used to work with the short slot (1-4) to weaken the electromagnetic coupling between the H-shaped patch (1-1) and the square patch (1-2); The bottom metal structure (2) is a rectangular metal ground; three coaxial probes (5) are inserted from the bottom surface of the bottom metal structure (2) upwards and are connected to the H-shaped patch (1-1) and the two square patches (1-2) respectively; Three metallized vias (4) pass vertically through the top layer patch (1), the middle layer dielectric substrate (3), and the bottom layer metal structure (2). One of the metallized vias (4) is located on the horizontal symmetry line of the antenna structure, and the other two metallized vias (4) are symmetrically distributed on the vertical symmetry line. The top of the three metallized vias (4) is connected to the H-type patch (1-1) and two square patches (1-2) respectively. Three circular grooves (2-1) are provided on the rectangular metal ground, and the ends of each metallized via (4) are located in the center of the circular grooves (2-1) respectively. The inner conductors of the three coaxial probes (5) are inserted into the metallized vias (4) and connected to the H-type patch (1-1) and the square patch (1-2) respectively. The outer conductors of the coaxial probes (5) are connected to the rectangular metal ground. When a low-frequency signal is fed in through one of the coaxial probes connected to the H-shaped patch (1-1), and a high-frequency signal is fed in through the other two coaxial probes connected to the two square patches (1-2) respectively, the low-frequency unit frequency sweep and the high-frequency subarray side-emitting function are realized. When the coaxial probes connecting the two square patches (1-2) are excited in opposite phase, the high-frequency subarray is realized and the vertically polarized subarray side-radiation is obtained.

2. The patch antenna according to claim 1, characterized in that, The length of the H-type patch (1-1) is 0.97λ. 01 -1.07λ 01 Between, with a width of 0.86λ 01 -0.96λ 01 Between, λ 01 The free-space wavelength corresponds to the center frequency of the low-frequency patch antenna; the side length of the square patch (1-2) is 0.285λ. 02 -0.395λ 02 Between, λ 02 The free-space wavelength corresponds to the center frequency of the high-frequency patch antenna; the slot spacing of the parallel slots (1-3) is 0.05λ. 01 -0.14λ 01 Between, the groove length is 0.15λ 01 -0.45λ 01 Between; the length of the short grooves (1-4) is between 0.01λ. 01 -0.06λ 01 between.

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