Dual-frequency shared aperture folded array antenna

Abstract

The application provides a dual-frequency shared aperture folded array antenna, and relates to the technical field of array antennas, which comprises a dual-frequency polarization converter and a linear polarization twist reflection surface arranged in an up-down mode; the dual-frequency polarization converter comprises a plurality of dual-frequency polarization conversion surface units arranged periodically; the dual-frequency polarization conversion surface unit has polarization selection characteristics, and can reflect an incident y-polarized electromagnetic wave and twist and transmit an incident x-polarized electromagnetic wave into a y-polarized electromagnetic wave at a high frequency; at a low frequency, the dual-frequency polarization conversion surface unit can transmit an incident x-polarized electromagnetic wave without polarization twist. The structure can be applied to a folded array, and the overall profile of the array is reduced. The dual-frequency shared aperture folded array antenna has polarization selection characteristics, the profile can be reduced by one third by introducing a polarization converter, the overall antenna has a small number of layers, the structure is simple, the antenna is easy to process, and the cost is low.

Description

Technical Field

[0001] This invention relates to the field of array antenna technology, specifically to a dual-frequency shared-aperture folded array antenna. Background Technology

[0002] With the rapid development of wireless communication technology, fields such as 5G / 6G communication and satellite communication have placed higher demands on antenna performance. On the one hand, dual-band high-gain antennas need to achieve multi-band coverage in a compact space. Traditional independent antenna deployment methods occupy a large amount of space, while common aperture design can solve this problem through 100% aperture reuse efficiency, meeting the future wireless system's requirements for space compactness and multi-band communication.

[0003] The dual-band common-aperture folded transmission array antenna effectively solves several key problems existing in current dual-band antennas, traditional transmission arrays, and reflection arrays by using dual-band unit common-aperture multiplexing and a folded transmission array structure. It allows high and low frequency bands to share the same radiation aperture, avoiding the problems of large size, crowded layout, and severe inter-band coupling caused by two sets of antennas. At the same time, it achieves independent phase modulation of the two bands, ensuring that the radiation performance of different bands does not interfere with each other. The folded structure significantly reduces the overall antenna profile, solving the defects of long focal length and excessively high profile of traditional transmission arrays. Furthermore, placing the feed on the side or back eliminates the problems of reduced aperture efficiency and reduced gain caused by feed obstruction. In addition, this structure simplifies the complex dual-band feed network, reduces transmission loss, and improves system integration and stability. Ultimately, it achieves low profile, high gain, high isolation, and high aperture utilization dual-band integrated radiation, which effectively makes up for the shortcomings of traditional antennas in miniaturization, integration, and dual-band collaborative operation.

[0004] Therefore, this research on dual-frequency shared aperture antennas has significant engineering value and theoretical significance for promoting the development of wireless and satellite communication technologies. Summary of the Invention

[0005] Therefore, this invention provides a dual-band shared-aperture folded array antenna to solve the above-mentioned problems; the dual-band shared-aperture folded array antenna provided by this invention can achieve a wider bandwidth with a lower profile. The antenna uses linear polarization feeding and transmits linearly polarized electromagnetic waves through a Fabry-Porosilicate cavity antenna, which can achieve polarization conversion, torsion, and selectivity performance.

[0006] This invention provides a dual-band shared-aperture folded array antenna, the structure of which includes a dual-band polarization converter and a linearly polarized torsional reflector surface arranged vertically. The dual-band polarization converter includes a plurality of periodically arranged dual-band polarization conversion surface units. Each dual-band polarization conversion surface unit includes, from top to bottom, an upper metal patch layer, an upper dielectric substrate layer, an adhesive layer, an intermediate metal layer, a lower dielectric substrate layer, and a lower metal patch layer stacked sequentially. The upper metal patch layer is a square metal patch. The intermediate metal layer is etched with arrow-shaped slots. The lower metal patch layer is a square metal patch. The linearly polarized torsional reflector surface includes, from top to bottom, a metal patch layer and a dielectric substrate layer with a metal ground layer. The metal patch layer includes periodically arranged arrow-shaped metal patches. A linearly polarized feed horn is hollowed out at the center of the linearly polarized torsional reflector surface, and coaxially fed patch antennas are arranged on both sides.

[0007] Furthermore, the linearly polarized electromagnetic wave output by the feed horn is incident on the lower surface of the dual-frequency polarization converter and reflected onto the linearly polarized torsional reflective surface; the linearly polarized electromagnetic wave output by the patch antenna is incident on the lower surface of the dual-frequency polarization converter and transmitted from its upper surface.

[0008] Furthermore, the linearly polarized torsional reflective surface receives linearly polarized electromagnetic waves through a metal patch layer. The torsional linearly polarized electromagnetic waves are reflected onto the lower metal patch layer of several dual-frequency polarization conversion metasurface units of the dual-frequency polarization converter, and transmitted to the upper metal patch layer through the intermediate metal patch.

[0009] Furthermore, the dual-frequency polarization converter achieves 2-bit phase coverage at high frequencies by changing the arrow slit length, and rotating the intermediate metal patch without changing the transmission amplitude under linear polarized wave incidence.

[0010] The present invention has the following advantages over the prior art:

[0011] 1. The dual-frequency polarization conversion surface unit proposed in this invention has polarization selectivity characteristics. It can reflect incident y-polarized electromagnetic waves at high frequencies and twist and transmit incident x-polarized electromagnetic waves as y-polarized electromagnetic waves; at low frequencies, it can transmit x-polarized electromagnetic waves. It can be applied to folded reflective arrays to reduce the overall cross-section of the array.

[0012] 2. The dual-frequency polarization conversion surface unit proposed in this invention can achieve 2-bit phase adjustment by rotating the intermediate metal patch layer and changing the arrow gap length, and can achieve linear phase in a wide frequency band.

[0013] 3. Due to its polarization selectivity, the present invention can reduce the profile by one-third by introducing a polarization converter; the overall antenna has fewer layers, a simpler structure, is easier to manufacture, and has a lower cost. Attached Figure Description

[0014] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0015] Figure 1 This is a schematic diagram of the three-dimensional structure of the antenna according to an embodiment of the present invention;

[0016] Figure 2 This is a side view of the antenna according to an embodiment of the present invention;

[0017] Figure 3 This is a top view of the dual-frequency polarization conversion surface of the antenna in an embodiment of the present invention;

[0018] Figure 4 This is a top view of the linearly polarized torsional reflective surface of the antenna in an embodiment of the present invention;

[0019] Figure 5 This is a three-dimensional structural diagram of a dual-frequency shared-aperture antenna unit according to an embodiment of the present invention;

[0020] Figure 6 This is a schematic diagram of the three-dimensional structure of the linearly polarized torsional reflective surface of the antenna according to an embodiment of the present invention;

[0021] Figure 7 This is a top view of the upper metal patch layer of the antenna in an embodiment of the present invention;

[0022] Figure 8 This is a top view of the intermediate metallic ground layer of the antenna in an embodiment of the present invention;

[0023] Figure 9 This is a top view of the lower metal patch layer of the antenna in an embodiment of the present invention;

[0024] Figure 10 This is a top view of the linearly polarized torsional reflection unit of the antenna in an embodiment of the present invention;

[0025] Figure 11 This is the low-frequency r of the dual-frequency polarization conversion metasurface unit of the antenna in this embodiment of the invention. xx Reflectance coefficient performance diagram;

[0026] Figure 12 This is the low-frequency t of the dual-frequency polarization conversion metasurface unit of the antenna in this embodiment of the invention. xx Transmission coefficient performance diagram;

[0027] Figure 13This is a low-frequency phase performance diagram of the dual-frequency polarization conversion metasurface unit of the antenna in an embodiment of the present invention;

[0028] Figure 14 The high-frequency t of the dual-frequency polarization conversion metasurface unit of the antenna in this embodiment of the invention. xy Transmission coefficient and phase response performance diagram;

[0029] Figure 15 The linearly polarized torsional reflection element of the antenna in this embodiment of the invention has a low-frequency r xx Reflectance coefficient performance diagram;

[0030] Figure 16 The linearly polarized torsional reflection element of the antenna in this embodiment of the invention has a low-frequency r yx Reflectance coefficient performance diagram;

[0031] Figure 17 These are the E-plane and H-plane radiation patterns of the antenna of the present invention with primary polarization at the center frequency in the low-frequency band and the E-plane and H-plane radiation patterns with cross polarization at the center frequency in the low-frequency band.

[0032] Figure 18 This is a graph showing the gain-frequency variation performance of the antenna at low frequencies according to the present invention.

[0033] Figure 19 These are the E-plane and H-plane radiation patterns of the antenna of the present invention with the main polarization of the high-frequency center frequency and the E-plane and H-plane radiation patterns of the cross-polarization of the high-frequency center frequency.

[0034] Figure 20 This is a graph showing the gain-frequency variation performance of the antenna of this invention at high frequencies.

[0035] Explanation of reference numerals in the attached figures:

[0036] 1. Dual-frequency polarization conversion surface unit; 2. Linear polarization torsional reflective surface; 3. Upper metal patch layer; 4. Upper dielectric substrate layer; 5. Adhesive layer; 6. Middle metal ground layer; 7. Lower dielectric substrate layer; 8. Lower metal patch layer; 9. Metal patch layer; 10. Dielectric substrate layer; 11. Metal ground layer; 12. Feed horn; 13. Coaxial patch antenna feed. Detailed Implementation

[0037] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0038] Example 1

[0039] This embodiment provides a dual-band shared aperture folded array antenna, the structure of which is as follows: Figures 1 to 9 As shown; it includes a dual-frequency polarization converter and a linearly polarized torsional reflector 2 arranged vertically; the dual-frequency polarization converter includes several periodically arranged adjustable phase polarization conversion surface units 1; the dual-frequency polarization conversion surface unit 1 includes an upper metal patch layer 3, an upper dielectric substrate layer 4, an adhesive layer 5, an intermediate metal layer 6, a lower dielectric substrate layer 7, and a lower metal patch layer 8 stacked sequentially from top to bottom; the upper metal patch layer 3 is a square metal patch; the intermediate metal ground layer 6 is etched with arrow-shaped slots; the lower metal patch layer 8 is a square metal patch; the linearly polarized torsional reflector 2 includes a metal patch layer 9 and a dielectric substrate layer 10 stacked sequentially from top to bottom, and a metal ground layer 11; the metal patch layer 9 includes periodically arranged arrow-shaped metal patches; the center of the linearly polarized torsional reflector 2 is hollowed out with a linearly polarized feed horn 12, and coaxial patch antenna feeds 13 are arranged on both sides.

[0040] like Figure 2 As shown, the feed horn 12 outputs a y-polarized electromagnetic wave, which is incident on the lower surface of the dual-frequency polarization converter. Due to the polarization selectivity of the dual-frequency polarization converter, the y-polarized electromagnetic wave cannot pass through this structure at high frequencies, but is reflected onto the linearly polarized torsional reflective surface 2. The linearly polarized torsional reflective surface 2 torsionalizes the y-polarized electromagnetic wave into an x-polarized electromagnetic wave, which is then incident again on the lower surface of the tunable phase polarization converter. Due to the polarization selectivity of the tunable phase polarization converter, the x-polarized electromagnetic wave is received through the lower metal patch layer 8, transmitted through the intermediate metal ground layer 6 to the upper metal patch layer 3, and torsionalized into a y-polarized electromagnetic wave with corresponding phase compensation. At low frequencies, the x-polarized electromagnetic wave can pass directly through this structure without polarization torsion.

[0041] Example 2

[0042] This embodiment simulates an antenna obtained using the parameters in Table 1 below, based on Embodiment 1.

[0043] Table 1: Antenna Parameter Table

[0044] parameter p Ls Ws ee m dd Value (mm) 3.5 1.7 0.787 2.4 0.65 0.6 parameter <![CDATA[h1]]> <![CDATA[h2]]> <![CDATA[h3]]> Value (mm) 0.305 0.202 0.508

[0045] p is the side length of the dielectric substrate, Ls is the width of the upper metal patch, Ws is the length of the upper metal patch layer 3, and h 1, h3 is the height of the dielectric substrate, h2 is the height of the adhesive layer, ee is the length of the intermediate metal ground layer 6, ee-1.4m is the length of the arrow-shaped slot in the intermediate metal ground layer 6, and dd is the width of the arrow-shaped slot in the intermediate metal ground layer 6.

[0046] like Figure 5As shown, the upper dielectric substrate layer 4 and the lower dielectric substrate layer 7 of the dual-frequency polarization conversion surface unit 1 are made of the same material and have the same size. Their dielectric constant εr is 3.55, tanδ is 0.0027, height h1 is 0.305 mm, and height h3 is 0.508 mm. The dielectric constant εr of the adhesive layer 5 is 3.52, tanδ is 0.004, and height h2 is 0.202 mm. Furthermore, the linearly polarized torsional reflective surface 2 has a dielectric constant εr of 3.55, tanδ of 0.0027, and a height of 1.508 mm.

[0047] like Figure 7 As shown, the xoy plane of the dual-frequency polarization conversion surface unit 1 is a square structure with a side length p of 0.35λ and a metal patch with a length of Ws and a width of Ls.

[0048] like Figure 8 As shown, the intermediate metal layer 6 of the dual-frequency polarization conversion surface unit 1 has a J-shaped arrow-shaped slit structure, the side length of the metal patch is ee, the length of the arrow slit is ee-1.4m, and the width of the arrow slit is dd.

[0049] like Figure 9 As shown, the xoy plane of the dual-frequency polarization conversion surface unit 1 is a square structure with a side length p of 0.35λ. The metal patch has a length of p and a width of S1.

[0050] like Figure 10 As shown, a single linearly polarized torsional reflective surface has an arc-shaped arrowhead structure with an arrowhead width of L1.

[0051] like Figure 11 As shown in Figures 12 and 13, the reflection coefficient and phase change of the dual-frequency polarization conversion surface unit 1 within the frequency range are given by r. xx and t xx At a center frequency of 6.4 GHz, the amplitudes are -3.7 dB and -2.5 dB, respectively, and the phase remains unchanged.

[0052] like Figure 14 As shown, the reflection coefficient and phase change of the dual-frequency polarization conversion surface unit 1 within the frequency range are given by t. xy With the center frequency remaining constant at approximately -1dB at 30GHz, and a phase difference of 90°, rotating the unit allows for an additional 180° phase change, resulting in a total of 2-bit phase compensation.

[0053] like Figure 15 As shown in Figure 16, a single linearly polarized torsional reflector has no polarization torsion in the 5-10 GHz frequency range, and the reflection amplitude is close to 0 dB; in the 22-35 GHz frequency range, it has polarization torsion, and the reflection amplitude is greater than -1 dB.

[0054] like Figure 17 As shown, the dual-band shared aperture folded array antenna has a main polarization of approximately 13.8 dB at a center frequency of 6.4 GHz;

[0055] like Figure 18 As shown, the antenna has a 17% 3 dB gain bandwidth and a 25% aperture efficiency in the 5.8-6.9 GHz frequency range.

[0056] like Figure 19 As shown, the dual-band shared aperture folded array antenna has a main polarization of about 24 dB at the center frequency of 30 GHz.

[0057] like Figure 20 As shown, the antenna has a 3 dB gain bandwidth of 20.4% and an aperture efficiency of 25% in the 28-35 GHz frequency range.

[0058] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A dual-frequency shared-aperture folded array antenna, characterized in that, include: A dual-frequency polarization converter is provided below which a linearly polarized torsional reflective surface (2); the dual-frequency polarization converter includes a number of periodically arranged dual-frequency polarization conversion surface units (1).

2. The dual-frequency shared-aperture folded array antenna according to claim 1, characterized in that, The dual-frequency polarization conversion surface unit (1) includes an upper metal patch layer (3), an upper dielectric substrate layer (4), an adhesive layer (5), an intermediate metal layer (6), a lower dielectric substrate layer (7), and a lower metal patch layer (8) stacked sequentially from top to bottom; the upper metal patch layer (3) is a square metal patch; the intermediate metal ground layer (6) is etched with arrow-shaped slots; and the lower metal patch layer (8) is a square metal patch.

3. The dual-frequency shared-aperture folded array antenna according to claim 2, characterized in that, The linearly polarized torsional reflective surface (2) includes a metal patch layer (9), a dielectric substrate layer (10), and a metal ground layer (11) stacked sequentially from top to bottom; the metal ground layer (11) is a whole square metal patch.

4. The dual-frequency shared-aperture folded array antenna according to claim 3, characterized in that, The metal patch layer (9) is provided with multiple arc-shaped arrow structures.

5. The dual-frequency shared-aperture folded array antenna according to claim 4, characterized in that, The linearly polarized torsional reflective surface (2) has a hollowed-out center with a linearly polarized feed horn (12) as a high-frequency feed, and two coaxial patch antenna feeds (13) next to the horn as low-frequency feeds.

6. The dual-frequency shared-aperture folded array antenna according to claim 5, characterized in that, The feed horn (12) outputs y-polarized electromagnetic waves, which are incident on the lower surface of the dual-frequency polarization converter and reflected onto the linearly polarized torsional reflective surface (2). (2) then reflects x-polarized electromagnetic waves onto the lower surface of the dual-frequency polarization converter and transmits y-polarized electromagnetic waves from the upper surface. The patch antenna feed outputs x-polarized electromagnetic waves, which are incident on the lower surface of the dual-frequency polarization converter and transmit x-polarized electromagnetic waves from its upper surface.

7. The dual-frequency shared-aperture folded array antenna according to claim 6, characterized in that, The linearly polarized torsional reflective surface (2) receives linearly polarized electromagnetic waves through the metal patch layer (9). The torsional linearly polarized electromagnetic waves are reflected onto the lower metal patch layer (8) of several dual-frequency polarization conversion metasurface units (1) of the dual-frequency polarization converter, and transmitted to the upper metal patch layer (3) through the metal gap (6).

8. The dual-frequency shared-aperture folded array antenna according to claim 7, characterized in that, The dual-frequency polarization converter achieves 2-bit phase coverage at high frequencies by changing the length of the arrow slit and rotating the middle metal patch without changing the transmission amplitude under linear polarization wave incidence.

9. The dual-frequency shared-aperture folded array antenna according to claim 8, characterized in that, The upper metal patch layer (3) and the lower metal patch layer (8) of the dual-frequency polarization converter are orthogonal metal patches, which effectively reflect the same-direction linearly polarized electromagnetic waves through the resonance of the middle metal layer (6).

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