A highly integrated, low-profile, wide-angle scanning microstrip antenna array in the X-band

Abstract

The present invention discloses a highly integrated, low-profile, wide-angle scanning microstrip antenna array in the X-band, belonging to the field of microwave antenna technology. The antenna array of the present invention comprises a number of periodically arranged unit antennas, and the unit antenna comprises an antenna radiation layer, a feeding layer, and a reflection cavity layer that are crimped sequentially from top to bottom. The antenna of the present invention adopts a quasi-coaxial structure for feeding to achieve high integration of the microstrip antenna array and the integrated feeding board; adopts a microstrip antenna form to achieve a low profile of the array; adopts a through-air reflection cavity, which makes it easier to realize the process of the microstrip antenna array, and meets the beam scanning characteristics of ±30° in the azimuth plane and the pitch plane within 40% of the relative bandwidth of the X-band.

Description

Technical Field

[0001] The present invention belongs to the technical field of microwave antennas, and in particular relates to an X-band high-integration, low-profile, wide-angle scanning microstrip antenna array. Background Art

[0002] Phased array systems have been widely used in communications, radar and other fields due to their fast beam scanning, simultaneous multi-functions and modularity. With the continuous development of various types of equipment, requirements such as large-angle scanning, modularization and integrated design have gradually become mainstream requirements.

[0003] Microstrip antennas are a common choice for broadband array antennas requiring low profiles, large scanning angles, and high integration. Compared to conventional microwave antennas, microstrip antennas offer low profiles, small size, and light weight. They feature a planar structure that conforms to the carrier surface. They can be integrated with active circuits and mass-produced using printed circuit technology, making them easy to process and inexpensive. Existing feeding methods for microstrip patch antennas include coaxial probes, microstrip lines, progressive coupling, aperture coupling, L-shaped probes, and coplanar waveguides. Coaxial probes and microstrip line feeding methods have bandwidths of approximately 1% to 7%, while progressive coupling, aperture coupling, and coplanar waveguide feeding methods require alignment during processing and have bandwidths of approximately 13%, 26%, and 3%, respectively. L-shaped probes, however, require complex processing and have a bandwidth of approximately 28%. Existing technologies cannot simultaneously meet the requirements of a 40% relative bandwidth, easy processing, high integration, low profile, and wide-angle scanning. Summary of the Invention

[0004] The object of the present invention is to overcome the above-mentioned defects of the prior art and provide an X-band highly integrated, low-profile, wide-angle scanning microstrip antenna array.

[0005] The technical problem proposed by the present invention is solved as follows:

[0006] An X-band highly integrated, low-profile, wide-angle scanning microstrip antenna array comprises M×N periodically arranged unit antennas, where M and N are positive integers.

[0007] The unit antenna includes an antenna radiation layer 1, a feed layer 2 and a reflection cavity layer 3 which are crimped in sequence from top to bottom;

[0008] The antenna radiation layer 1 includes a first printed circuit board 5, a first prepreg 7, a second printed circuit board 6 and a second prepreg 8 which are press-bonded from top to bottom, and a radiation patch 4 located on the upper surface of the first printed circuit board 5;

[0009] The feed layer 2 includes a third printed board 9, a feed microstrip line 10, and a feed core 11. The feed microstrip line 10 is located on the upper surface of the third printed board 9, parallel to the edge of the third printed board 9, extending from the center to the edge and leaving a gap with the edge. The feed core 11 passes through the third printed board 9, and one end is connected to the end of the feed microstrip line 10 near the edge of the third printed board 9.

[0010] The reflection cavity layer 3 includes a third prepreg 15, a fourth printed circuit board 12, a fourth prepreg 16, a fifth printed circuit board 13, a fifth prepreg 17, a sixth printed circuit board 14 and a sixth prepreg 18 which are pressed together from top to bottom to form a multilayer structure. The multilayer structure is partially etched to form a rectangular air cavity 19. The long side of the rectangular air cavity is perpendicular to the feed microstrip line 10 and extends to both ends of the multilayer structure. The width spans the radiation patch 4. The bottom of the rectangular air cavity and the rectangular air cavity are connected to the radiation patch 4. Metal edging 22 is provided between the contact surface of the multilayer structure, the third prepreg 15 and the fourth printed circuit board 12; a number of metalized vias penetrate the multilayer structure, the central metalized via 20 is connected to the feed core 11, and the peripheral metalized vias 21 are arranged around the central metalized via 20 with a distribution interval of 60°; the metal edging 22 has circular etching portions at the corresponding positions of the central metalized via 20 and the peripheral metalized vias 21, and the circumference of the circular etching portion passes through the center of the peripheral metalized via 21.

[0011] Furthermore, the unit antenna is square, with a period of 16 mm in both the azimuth and elevation planes; the unit antenna is arranged in a rectangular arrangement, with a cross-sectional height of 6.43 mm.

[0012] Furthermore, the dielectric constant of the first printed board 5 and the second printed board 6 is 2.2, and the thickness is 1.51 mm; the radiation patch is square with a side length of 4.6 mm, and the side is parallel to the side of the first printed board 5.

[0013] Furthermore, the dielectric constant of the third printed circuit board 9 is 2.2, and the thickness is 0.51 mm; the line width of the feeding microstrip line 10 is 2.32 mm, the length is 7.78 mm, and the outer diameter of the feeding core 11 is 0.6 mm.

[0014] Furthermore, the dielectric constant of the fourth printed board 12, the fifth printed board 13 and the sixth printed board 14 is 2.2, and the thickness is 0.76 mm; the diameter of the metallized via hole is 0.6 mm, and the circumferential diameter of the circular etched portion is 1.92 mm.

[0015] Furthermore, the width of the rectangular air cavity 19 is 5.63 mm.

[0016] The beneficial effects of the present invention are:

[0017] This invention implements an X-band microstrip antenna array with a cross-sectional height of 6.43mm, capable of beam scanning within ±30° in azimuth and elevation within 40% of the X-band relative bandwidth. The use of a quasi-coaxial feed structure achieves high integration of the microstrip antenna array and the integrated feed board. The microstrip antenna form factor achieves a low profile, and the use of a through-hole air reflection cavity facilitates the fabrication of the microstrip antenna array. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 Schematic diagram of the structure of the unit antenna in the array of the present invention, wherein (a) is a front view, (b) is a top view, (c) is a bottom view, (d) is a side view, and (e) is an exploded view;

[0019] Figure 2 Schematic diagram of the structure of the array of the present invention, wherein (a) is a front view, (b) is a top view, (c) is a bottom view, and (d) is a side view;

[0020] Figure 3 : are the directional patterns of the unit antennas in the array described in the embodiment, where (a) is the E-plane directional pattern and (b) is the H-plane directional pattern. DETAILED DESCRIPTION

[0021] The present invention will be further described below with reference to the accompanying drawings and examples.

[0022] This embodiment provides an X-band highly integrated, low-profile, wide-angle scanning microstrip antenna array, the front view of which is shown in FIG. Figure 2 (a) shows the top view. Figure 2 (b) shows the bottom view. Figure 2 (c) shows the side view. Figure 2 As shown in (d), it includes M×N unit antennas arranged periodically, where M and N are positive integers;

[0023] The front view of the unit antenna is as follows Figure 1 (a) shows the top view. Figure 1 (b) shows the bottom view. Figure 1 (c) shows the side view. Figure 1 (d) shows the exploded diagram. Figure 1 As shown in (e), it includes an antenna radiation layer 1, a feed layer 2, and a reflection cavity layer 3 which are crimped sequentially from top to bottom;

[0024] The antenna radiation layer 1 includes a first printed circuit board 5, a first prepreg 7, a second printed circuit board 6 and a second prepreg 8 which are press-bonded from top to bottom, and a radiation patch 4 located on the upper surface of the first printed circuit board 5;

[0025] The feed layer 2 includes a third printed board 9, a feed microstrip line 10, and a feed core 11. The feed microstrip line 10 is located on the upper surface of the third printed board 9, parallel to the edge of the third printed board 9, extending from the center to the edge and leaving a gap with the edge. The feed core 11 passes through the third printed board 9, and one end is connected to the end of the feed microstrip line 10 near the edge of the third printed board 9.

[0026] The reflective cavity layer 3 includes a third prepreg 15, a fourth printed circuit board 12, a fourth prepreg 16, a fifth printed circuit board 13, a fifth prepreg 17, a sixth printed circuit board 14, and a sixth prepreg 18, which are crimped sequentially from top to bottom to form a multilayer structure. The multilayer structure is partially etched to form a rectangular air cavity. Metal edging 22 is provided at the bottom of the rectangular air cavity, the contact surface between the rectangular air cavity and the multilayer structure, and between the third prepreg 15 and the fourth printed circuit board 12. Several metalized vias penetrate the multilayer structure, the central metalized via 20 connects to the feed core 11, and the peripheral metalized vias 21 are arranged around the central metalized via 20 with a distribution interval of 60°. The metal edging 22 has circular etched portions at the corresponding positions of the central metalized via 20 and the peripheral metalized vias 21, and the circumference of the circular etched portion passes through the center of the peripheral metalized via 21.

[0027] When the unit antenna is working, the RF signal is transmitted to the feed microstrip line 10 through the coaxial structure formed by the central metallized via 20 and the peripheral metallized via 21, and then reflected by the metal cladding 22 and radiated into the free space through the radiation patch 4; the resonant cavity formed by the metal cladding 22 is used here as a reflection cavity to widen the frequency band.

[0028] In this embodiment, the antenna radiating layer 1 has square antenna elements with a period of 16 mm in both the azimuth and elevation planes. The antenna elements are arranged in a rectangular pattern with a cross-sectional height of 6.43 mm. The first and second printed circuit boards 5 and 6 have a dielectric constant of 2.2 and a thickness of 1.51 mm. The radiating patch is square with a side length of 4.6 mm, parallel to the sides of the first printed circuit board 5.

[0029] In the feed layer 2 , the third printed board 9 has a dielectric constant of 2.2 and a thickness of 0.51 mm; the feed microstrip line 10 has a line width of 2.32 mm and a length of 7.78 mm; and the outer diameter of the feed core 11 is 0.6 mm.

[0030] In the reflective cavity layer 3, the fourth, fifth, and sixth printed circuit boards 12, 13, and 14 have a dielectric constant of 2.2 and are all 0.76 mm thick. The diameter of the metallized vias is 0.6 mm, and the circumference of the circular etched portion is 1.92 mm. The width of the rectangular air cavity 19 is 5.63 mm.

[0031] The measured directional pattern of the array unit is as follows Figure 3As shown in the figure, (a) is the E-plane pattern, and (b) is the H-plane pattern. The pattern of the array unit is tapered within ±30° in the azimuth and elevation planes to meet the 3dB scanning loss requirement, and the beam scanning characteristics of ±30° in the azimuth and elevation planes can be achieved.

[0032] In this embodiment of the highly integrated, low-profile, wide-angle scanning X-band microstrip antenna array, the rectangular air cavity 19 and its surrounding metal cladding 22 form a through-structure air reflection cavity, which simplifies manufacturing and meets the ±30° beam scanning characteristics in azimuth and elevation within the X-band. This embodiment utilizes a quasi-coaxial feed structure to achieve high integration of the microstrip antenna array and integrated feed board; the microstrip antenna form factor achieves a low profile; and the through-structure air reflection cavity facilitates manufacturing of the microstrip antenna array.

Claims

1. An X-band highly integrated, low-profile, wide-angle scanning microstrip antenna array, characterized in that: It includes M×N unit antennas arranged periodically, where M and N are positive integers; The unit antenna comprises an antenna radiation layer (1), a feed layer (2) and a reflection cavity layer (3) which are crimped in sequence from top to bottom; The antenna radiation layer (1) includes a first printed board (5), a first prepreg (7), a second printed board (6) and a second prepreg (8) which are press-bonded in sequence from top to bottom, and a radiation patch (4) located on the upper surface of the first printed board (5); The feed layer (2) includes a third printed board (9), a feed microstrip line (10) and a feed core (11); the feed microstrip line (10) is located on the upper surface of the third printed board (9), is parallel to the edge of the third printed board (9), extends from the center to the edge and has a spacing from the edge; the feed core (11) passes through the third printed board (9), and one end is connected to the end of the feed microstrip line (10) close to the edge of the third printed board (9); The reflection cavity layer (3) includes a third prepreg (15), a fourth printed board (12), a fourth prepreg (16), a fifth printed board (13), a fifth prepreg (17), a sixth printed board (14) and a sixth prepreg (18) which are press-bonded in sequence from top to bottom to form a multi-layer structure; the multi-layer structure is partially etched to form a rectangular air cavity (19); the long side of the rectangular air cavity is perpendicular to the feed microstrip line (10) and extends to both ends of the multi-layer structure, and the width spans the radiation patch (4); the bottom of the rectangular air cavity, the rectangular air cavity and the Metal edging (22) is provided between the contact surface of the multilayer structure, the third prepreg (15) and the fourth printed circuit board (12); a plurality of metalized vias penetrate the multilayer structure, the central metalized via (20) is connected to the feed core (11), and the peripheral metalized vias (21) are arranged around the central metalized via (20) with a distribution interval of 60 degrees; the metal edging (22) has circular etching portions at corresponding positions of the central metalized via (20) and the peripheral metalized via (21), and the circumference of the circular etching portion passes through the center of the peripheral metalized via (21).

2. The X-band highly integrated, low-profile, wide-angle scanning microstrip antenna array according to claim 1, characterized in that: The unit antenna is square, with a period of 16 mm in both the azimuth and elevation planes; the unit antenna is arranged in a rectangular pattern with a cross-sectional height of 6.43 mm.

3. The X-band highly integrated, low-profile, wide-angle scanning microstrip antenna array according to claim 1, characterized in that: The dielectric constant of the first printed board (5) and the second printed board (6) is 2.2, and the thickness is 1.51 mm; the radiation patch is square, with a side length of 4.6 mm, and the side is parallel to the side of the first printed board (5).

4. The X-band highly integrated, low-profile, wide-angle scanning microstrip antenna array according to claim 1, characterized in that: The dielectric constant of the third printed board (9) is 2.2 and the thickness is 0.51 mm; the line width of the feed microstrip line (10) is 2.32 mm and the length is 7.78 mm; the outer diameter of the feed core (11) is 0.6 mm.

5. The X-band highly integrated, low-profile, wide-angle scanning microstrip antenna array according to claim 1, characterized in that: The dielectric constant of the fourth printed board (12), the fifth printed board (13) and the sixth printed board (14) is 2.2, and the thickness is 0.76 mm; the diameter of the metallized via hole is 0.6 mm, and the circumferential diameter of the circular etched portion is 1.92 mm.

6. The X-band highly integrated, low-profile, wide-angle scanning microstrip antenna array according to claim 1, characterized in that: The width of the rectangular air cavity (19) is 5.63 mm.

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