Based on the side of the etching microstrip line type broadband beam patch array antenna

Abstract

The application discloses an etching microstrip line type broadband beam patch array antenna based on side edge feeding, which comprises an antenna array layer, an integrated waveguide layer and a grounding layer arranged in sequence; the antenna array layer is composed of linear arrangement of a plurality of antenna units; the antenna unit comprises a feeding line, one end of the feeding line is connected with a rectangular transmission line, and one side of the rectangular transmission line is connected with a plurality of radiation units; the rectangular transmission line is provided with a first rectangular groove, a second rectangular groove and a third rectangular groove, thereby forming an H-shaped feeding network for side edge feeding of the plurality of radiation units. The array antenna of the application works in a 75GHz-85GHz frequency range, the beam width of an E plane is from -22° to 24°, the beam width of an H plane is from -40° to 40°, and the beam width is from -18° to 24° at 78GHz, thereby realizing wide band and wide beam of the E plane and the H plane in the millimeter wave frequency range.

Description

Technical Field

[0001] This invention relates to the field of microwave device technology, and in particular to an etched microstrip linear wideband beampatch array antenna based on side feeding. Background Technology

[0002] With the rapid development of wireless communication technology, the demand for high-performance array antennas is increasing. Ultra-wideband, low-profile, wide-beam antennas have gradually become research hotspots. With the continuous advancement of technology, the research and application of wide-bandwidth beam antennas are constantly expanding. Satellite systems require antennas with relatively wide beam coverage to avoid multipath and tropospheric effects commonly seen in radar; base station systems require antennas with good directional beams; imaging systems require antennas with wide-bandwidth beams to improve resolution. With the continuous expansion of application scenarios, the research on broadband microstrip array antennas that satisfy wide beams in both the E-plane and H-plane has important theoretical significance and potential market value.

[0003] For traditional microstrip antennas, there are several feeding methods: electromagnetic coupling feeding, where the feed line and patch do not directly contact each other to reduce feed loss, and slotting can improve high-frequency impedance matching and effectively increase bandwidth, but the antenna thickness will increase, which is not conducive to miniaturization; coaxial feeding, where the outer conductor of the coaxial line can achieve electromagnetic shielding to avoid the influence of the feed on radiation, but the design is complex, limits physical size, and is difficult to integrate; microstrip line feeding can be fabricated and designed together with the patch to achieve integration, but the feed interferes with the radiation field of the microstrip patch, making it difficult to achieve high performance. Common power supply networks for arrays include series and parallel types. In series power supply networks, the current amplitude and phase on different array elements are adjusted by changing the size of the feed lines and the spacing between array elements. They generally operate under traveling wave conditions, have high space utilization, occupy little space, and have high radiation efficiency. However, phase deviations gradually accumulate between array elements, bandwidth is limited, and performance is difficult to optimize. Parallel power supply networks often use power dividers cascaded to provide excitation to array elements. They have good amplitude and phase control, beam pointing is independent of frequency, and the radiation pattern is matched within the frequency band. However, there are too many network levels, resulting in high transmission loss and low space utilization. Summary of the Invention

[0004] Based on the technical problems existing in the background technology, the present invention proposes an etched microstrip linear wideband beam patch array antenna based on side feeding, which can simultaneously achieve broadband and wide beams in both the E-plane and H-plane.

[0005] The side-fed etched microstrip linear wideband beamp array antenna proposed in this invention includes an antenna array layer, an integrated waveguide layer and a ground layer arranged sequentially.

[0006] The antenna array layer is composed of a number of antenna elements arranged linearly. Each antenna element includes a feed line, one end of which is connected to a rectangular transmission line. One side of the rectangular transmission line is connected to a number of radiating elements. The rectangular transmission line is provided with a first rectangular groove, a second rectangular groove, and a third rectangular groove, forming an H-shaped feed network for feeding the sides of the radiating elements.

[0007] Preferably, the dimensions of the rectangular transmission line are (2.2λ-2.4λ)*0.125λ; the dimensions of the first rectangular groove are (0.3λ-0.4λ)*0.075λ; the dimensions of the second rectangular groove are (0.16λ-0.18λ)*0.075λ; and the dimensions of the third rectangular groove are (0.2λ-0.4λ)*0.075λ; where λ is the electromagnetic wave wavelength of the array antenna.

[0008] Preferably, the radiating element includes a rectangular patch antenna, which is connected to the rectangular transmission line via an L-shaped connecting line.

[0009] Preferably, the rectangular patch antenna is further symmetrically provided with two fourth rectangular grooves, which are distributed on both sides of the connection between the L-shaped connecting line and the rectangular patch antenna; the size of the rectangular patch antenna is (0.25λ-0.29)λ*0.275λ, and the size of the fourth rectangular groove is (0.055λ-0.15λ)*(0.0375λ-0.0575λ); where λ is the electromagnetic wave wavelength of the array antenna.

[0010] Preferably, a transition microstrip is further provided between the L-shaped connecting line and the rectangular transmission line; the size of the transition microstrip is (0.13λ-0.24λ)*(0.03λ-0.075λ); where λ is the electromagnetic wave wavelength of the array antenna.

[0011] Preferably, the feed line is composed of GCPW on the antenna array layer and is distributed in a U-shape.

[0012] Preferably, the feed line has several top-level through holes on both sides, the integrated waveguide layer has waveguide through holes that match the top-level through holes, and the grounding layer has grounding through holes that match the waveguide through holes, so as to realize that the corresponding top-level through holes, waveguide through holes and grounding through holes are interconnected.

[0013] Preferably, the waveguide via has a radius of (0.03λ-0.06λ), a lateral spacing of (0.064λ-0.255λ), a longitudinal spacing of (0.08λ-0.125λ), and a height of 0.04λ-0.05λ; the distance between the top-layer via and the feed line is 0.12λ-0.14λ; where λ is the electromagnetic wave wavelength of the array antenna.

[0014] Preferably, the spacing between several antenna elements is 0.6λ-0.7λ, and the overall distribution is symmetrical; where λ is the electromagnetic wave wavelength of the array antenna.

[0015] Beneficial technical effects of the present invention:

[0016] 1. The array antenna of this invention employs a novel serial side-feed structure to feed multiple radiating elements. Signals are fed in series onto a rectangular transmission line via feed wires. The rectangular transmission line and each radiating element are connected via L-shaped lines to achieve the serial side-feed structure. Compared to traditional series-parallel feed networks, the serial side-feed structure proposed in this design is similar to a parallel feed network. The rectangular transmission line provides more uniform radiation coverage for the patch side-feeding, and structurally resembles a series feed network, allowing multiple radiating patches to have wider beamwidths at different frequency points, achieving both broadband and wide beamwidths in the E-plane and H-plane. Compared to a series-feed ultra-wideband microstrip array antenna for material detection developed by a domestic team, the array antenna of this invention operates in the 75 GHz frequency band. -85GHz, with a bandwidth 190% wider; compared with the K-band vehicle detection hybrid-fed microstrip array antenna developed by a team at Xi'an University of Electronic Science and Technology, the beamwidth of the antenna in this invention ranges from -22° to 24° at 76GHz, 78GHz, and 80GHz, and the beamwidth of the H-plane ranges from -40° to 40° at 76GHz and 81GHz, and from -18° to 24° at 78GHz. The beamwidth of both the E-plane and H-plane is greater than 2.5 times; at the same time, it achieves broadband and wide beamwidths in both the E-plane and H-plane.

[0017] 2. The array antenna of this invention designs an H-type feed network to distribute the excitation of the array elements. Compared with the traditional power-dividing parallel feed network, the structure is simpler, and the excitation distribution ratio can be changed by modifying the structure. Three rectangular grooves are etched on the rectangular transmission line. Compared with the traditional power-dividing parallel feed network, the signal is fed into the rectangular transmission line and then distributed to the radiating element through the H-type feed network. This transmission structure can also achieve the current ratio distributed to the radiating element, and the size of the three rectangular grooves can be changed to change the current distribution in the rectangular microstrip line, forming a uniform beamwidth at different frequency points. Moreover, compared with the power-dividing parallel feed network, the structure is simpler and has higher space utilization.

[0018] 3. The array antenna of this invention uses a microstrip line side-feed method to feed the patch antenna. The rectangular transmission line and each radiating element are connected by an L-shaped connecting line to achieve a serial side-feed structure, which overcomes the problems of narrow impedance bandwidth and limited performance of microstrip line feeding. The L-shaped connecting line increases the path length of current flowing through the patch antenna. Side feeding is conducive to flexible impedance matching and generates more resonant points. It can be seen that resonant points appear in the return loss at 77.5GHz, 79GHz, and 82.2GHz, achieving broadband. Compared with the average relative bandwidth of 5% of the traditional microstrip line-fed microstrip antenna, the relative bandwidth of the array antenna of this invention is 2.5 times the average relative bandwidth, and the return loss is below 10dB in the 75GHz-85GHz range. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the side-fed etched microstrip linear wideband beam patch array antenna proposed in this invention.

[0020] Figure 2 This is an exploded view of the side-fed etched microstrip linear wideband beam patch array antenna proposed in this invention.

[0021] Figure 3 This is a top view of the array antenna layer proposed in this invention;

[0022] Figure 4 This is a partially enlarged view of the single antenna element structure proposed in this invention;

[0023] Figure 5 This is a schematic diagram of the radiating element structure in a single antenna element proposed in this invention;

[0024] Figure 6 This is a schematic diagram of the integrated waveguide layer proposed in this invention;

[0025] Figure 7 The return loss parameters at the input port of the array antenna proposed in this invention Resulting image;

[0026] Figure 8 This is a diagram showing the beamwidth of the E-plane of the array antenna proposed in this invention.

[0027] Figure 9 This is a diagram showing the beamwidth of the H-plane of the array antenna proposed in this invention;

[0028] Figure 10 The image shows the imaging results of the microwave imaging system proposed in this invention using other wide-beam antennas and the array antenna of this invention.

[0029] In the diagram: 1-Antenna array layer, 11-Feed line, 12-Rectangular transmission line, 121-First rectangular groove, 122-Second rectangular groove, 123-Third rectangular groove, 13-First radiating element, 131-First transition microstrip, 132-L-shaped connecting line, 133-Fourth rectangular groove, 14-Second radiating element, 141-Second transition microstrip, 15-Third radiating element, 16-Fourth radiating element, 17-Top layer via, 2-Integrated waveguide layer, 21-Waveguide via, 3-Ground layer, 31-Ground via. Detailed Implementation

[0030] The present invention will be further explained below with reference to specific embodiments.

[0031] Reference Figure 1-4 The present invention proposes a side-fed etched microstrip line wideband beampatch array antenna, comprising an antenna array layer 1, an integrated waveguide layer 2, and a ground layer 3 arranged sequentially; the integrated waveguide layer 2 is made of Rogers 3003, has a thickness of 0.0325λ, and a dielectric constant of 3.07; the antenna array layer 1 and the ground layer 3 are made of copper; the lengths of the antenna array layer 1, the integrated waveguide layer 2, and the ground layer 3 are 15.525λ, 17.5λ, and 17.5λ, respectively, and the width of each is 15λ.

[0032] The antenna array layer 1 is composed of 1*8 antenna elements arranged linearly, with a spacing of 0.6λ-0.7λ between each antenna element, and the overall distribution is symmetrical; where λ is the electromagnetic wave wavelength of the array antenna; each antenna element includes a feed line 11, which is formed by GCPW on the antenna array layer 1 and distributed in a U-shape; one end of the feed line 11 is connected to a rectangular transmission line 12, and one side of the rectangular transmission line 12 is connected to several radiating elements. In this embodiment, the radiating elements include a first radiating element 13, a second radiating element 14, a third radiating element 15, and a fourth radiating element 16; the rectangular transmission line 12 is provided with a first rectangular groove 121, a second rectangular groove 122, and a third rectangular groove 123, forming an H-shaped feed network for feeding the sides of several radiating elements.

[0033] This application allows for alteration of the H-type feed network structure by adjusting the dimensions of the three rectangular grooves, thereby changing the current ratio distributed to the four radiating elements. Compared to traditional power-dividing parallel feed networks, this transmission structure can also control the current ratio distributed to the four radiating elements to change the amplitude and phase of the radiating elements, forming a uniform beamwidth at different frequency points, thus achieving a wide beam. Moreover, it is simpler in structure than parallel feed networks, with higher space utilization and higher radiation efficiency.

[0034] Specifically, the dimensions of the rectangular transmission line 12 are (2.2λ-2.4λ)*0.125λ; the dimensions of the first rectangular groove 121 are (0.3λ-0.4λ)*0.075λ; the dimensions of the second rectangular groove 122 are (0.16λ-0.18λ)*0.075λ; and the dimensions of the third rectangular groove 123 are (0.2λ-0.4λ)*0.075λ; where λ is the electromagnetic wave wavelength of the array antenna.

[0035] Reference Figure 5 For the radiating element, it includes a rectangular patch antenna, which is connected to the rectangular transmission line 12 via an L-shaped connecting line 132.

[0036] The rectangular patch antenna is also symmetrically provided with two fourth rectangular grooves 133, which are distributed on both sides of the connection between the L-shaped connecting line 132 and the rectangular patch antenna; the size of the rectangular patch antenna is (0.25λ-0.29)λ*0.275λ, and the size of the fourth rectangular groove 133 is (0.055λ-0.15λ)*(0.0375λ-0.0575λ); where λ is the electromagnetic wave wavelength of the array antenna.

[0037] Furthermore, a transition microstrip is provided between the L-shaped connecting line and the rectangular transmission line 12; the size of the transition microstrip is (0.13λ-0.24λ)*(0.03λ-0.075λ); where λ is the electromagnetic wave wavelength of the array antenna. In this embodiment, the L-shaped connecting line 132 of the first radiating element 13 is connected to the rectangular transmission line 12 through the first transition microstrip 131, and the L-shaped connecting line 132 of the second radiating element 14 is connected to the rectangular transmission line 12 through the second transition microstrip 141. The microstrip line side-feed structure of the radiating element is realized through the L-shaped connecting line and the transition microstrip line. This microstrip line side-feed connection between the radiating element and the serial side-feed structure achieves miniaturization.

[0038] Reference Figure 2 , Figure 3 and Figure 6 Each feeder wire 11 has a U-shaped path formed by a top-layer via 17 on both sides. The integrated waveguide layer 2 has a waveguide via 21 that matches the top-layer via 17, and the grounding layer 3 has a grounding via 31 that matches the waveguide via 21, so that the corresponding top-layer via 17, waveguide via 21 and grounding via 31 are interconnected. The top-layer via 17, waveguide via 21 and grounding via 31 are the same size and correspond one-to-one, forming a waveguide structure together with the feeder wire (11) formed by GCPW.

[0039] The waveguide via 21 has a radius of (0.03λ-0.06λ), a lateral spacing of (0.064λ-0.255λ), a longitudinal spacing of (0.08λ-0.125λ), and a height of 0.04λ-0.05λ; the distance between the top via 17 and the feed line 11 is 0.12λ-0.14λ; where λ is the electromagnetic wave wavelength of the array antenna.

[0040] Figure 7 Return loss parameters at the input port of the array antenna Resulting diagram. Return loss parameters at the array antenna input port. In the 75-85GHz frequency band The value is less than -10dB, achieving broadband.

[0041] Figure 8 The image shows the beamwidth of the E-plane of the array antenna. The beamwidth of the E-plane of the array antenna ranges from -22° to 24° at 76GHz, 78GHz, and 80GHz, achieving a wide beam.

[0042] Figure 9 The diagram shows the beamwidth results for the H-plane of the array antenna. The beamwidth of the H-plane of the array antenna ranges from -40° to 40° at 76 GHz and 81 GHz, and from -18° to 24° at 78 GHz, achieving a wide beam.

[0043] Figure 10 The images show the imaging results of the array antenna of this invention compared to other wide-beam antennas used in a microwave imaging system. It can be seen that the broadband and wide-beam performance of the array antenna of this invention in both the E and H planes result in better image clarity and higher resolution compared to traditional antennas that achieve wide beams using a single plane.

Claims

1. A side-fed etched microstrip linear wideband beampatch array antenna, characterized in that, It includes an antenna array layer (1), an integrated waveguide layer (2), and a ground layer (3) arranged sequentially. The antenna array layer (1) is composed of a number of antenna elements arranged linearly. The antenna element includes a feed line (11), one end of which is connected to a rectangular transmission line (12). One side of the rectangular transmission line (12) is connected to a number of radiating elements. The rectangular transmission line (12) is provided with a first rectangular groove (121), a second rectangular groove (122) and a third rectangular groove (123) to form an H-type feed network for feeding the sides of the number of radiating elements. The rectangular transmission line (12) has a size of (2.2λ-2.4λ)*0.125λ; the first rectangular groove (121) has a size of (0.3λ-0.4λ)*0.075λ; the second rectangular groove (122) has a size of (0.16λ-0.18λ)*0.075λ; and the third rectangular groove (123) has a size of (0.2λ-0.4λ)*0.075λ, where λ is the electromagnetic wave wavelength of the array antenna. The radiating element includes a rectangular patch antenna, which is connected to the rectangular transmission line (12) via an L-shaped connecting line (132).

2. The side-fed etched microstrip linear wideband beampatch array antenna according to claim 1, characterized in that, The rectangular patch antenna is also symmetrically provided with two fourth rectangular grooves (133), which are distributed on both sides of the connection between the L-shaped connecting line (132) and the rectangular patch antenna; the size of the rectangular patch antenna is (0.25λ-0.29)λ*0.275λ, and the size of the fourth rectangular groove (133) is (0.055λ-0.15λ)*(0.0375λ-0.0575λ); where λ is the electromagnetic wave wavelength of the array antenna.

3. The side-fed etched microstrip linear wideband beampatch array antenna according to claim 1, characterized in that, A transition microstrip is also provided between the L-shaped connecting line (132) and the rectangular transmission line (12); the size of the transition microstrip is (0.13λ-0.24λ)*(0.03λ-0.075λ); where λ is the electromagnetic wave wavelength of the array antenna.

4. The side-fed etched microstrip linear wideband beampatch array antenna according to claim 1, characterized in that, The feed line (11) is composed of GCPW on the antenna array layer (1) and is distributed in a U-shape.

5. The side-fed etched microstrip linear wideband beampatch array antenna according to claim 1, characterized in that, The feed line (11) has several top-level through holes (17) on both sides. The integrated waveguide layer (2) has waveguide through holes (21) that match the top-level through holes (17). The ground layer (3) has ground through holes (31) that match the waveguide through holes (21), so as to realize that the corresponding top-level through holes (17), waveguide through holes (21) and ground through holes (31) are interconnected.

6. The side-fed etched microstrip linear wideband beampatch array antenna according to claim 5, characterized in that, The waveguide via (21) has a radius of (0.03λ-0.06λ), a lateral spacing of (0.064λ-0.255λ), a longitudinal spacing of (0.08λ-0.125λ), and a height of 0.04λ-0.05λ; the distance between the top-layer via (17) and the feed line (11) is 0.12λ-0.14λ; where λ is the electromagnetic wave wavelength of the array antenna.

7. The side-fed etched microstrip linear wideband beampatch array antenna according to claim 1, characterized in that, The spacing between several antenna elements is 0.6λ-0.7λ, and the overall distribution is symmetrical; where λ is the electromagnetic wave wavelength of the array antenna.

8. The side-fed etched microstrip linear wideband beampatch array antenna according to claim 1, characterized in that, The array antenna operates in the 75GHz-85GHz frequency band, with an E-plane beamwidth ranging from -22° to 24° and an H-plane beamwidth ranging from -40° to 40°.

Images