Broadband circularly polarized multi-beam transmission array antenna based on SIW feed network

Abstract

The invention belongs to the technical field of wireless communication, and particularly relates to a broadband circularly polarized multi-beam transmission array antenna based on an SIW feed network. The antenna comprises a phase-adjustable polarization converter and a multi-beam circular polarization feed source which are arranged up and down; the phase-adjustable polarization converter comprises a plurality of receiving and re-transmitting units which are arranged periodically; the receiving and re-transmitting unit comprises an upper metal patch layer, an upper dielectric substrate layer, a middle metal grounding layer, a bonding layer, a lower dielectric substrate layer, a lower metal patch layer and a metal through hole which are sequentially stacked from top to bottom; the multi-beam circularly-polarized feed source comprises five circularly-polarized feed sources which are arranged straightly, and each circularly-polarized feed source comprises a 4 * 4 metasurface unit, an SIW upper dielectric substrate layer, an SIW upper metal wall, an SIW lower dielectric substrate layer and an SIW lower metal wall which are sequentially stacked from top to bottom. The antenna realizes + / -30-degree wave beam coverage, has the advantages of low profile, circular polarization, high gain and wide bandwidth, and can be used for millimeter wave application and satellite communication.

Description

Technical Field

[0001] The present invention belongs to the technical field of wireless communication, and particularly relates to a broadband circularly polarized multi-beam transmissive array antenna based on an SIW feeding network. Background Art

[0002] With the rapid development of the fifth-generation mobile communication technology (5G) and the upcoming sixth-generation mobile communication technology (6G), the requirements of wireless communication systems for high frequency bands, high capacity, high reliability, and low latency are continuously increasing. In this context, the millimeter-wave band has become an important research direction for the new generation of wireless communication due to its advantages such as wide bandwidth, large capacity, and high resolution.

[0003] Traditional multi-beam antennas are diverse and can be generally divided into phased array antennas, beamforming networks, lens antennas, and reflector multi-beam antennas according to their own structures and beamforming methods. Phased array antennas achieve flexible phase excitation through active devices. However, the high cost limits its application scenarios. Beamforming networks usually use matrices. When designing matrix networks, size reduction of the network, application of multi-layer boards, and lumped element loading are usually inevitable, while broadband performance and flexible beam control require complex crossover junctions and phase shifters. Lens multi-beam antennas and reflector multi-beam antennas have similar structural principles, and both use the focus of the lens or reflector to aggregate the electromagnetic waves radiated by the feed source and convert them into plane waves. Compared with reflector multi-beam antennas, lens multi-beam antennas are widely used because they can eliminate feed blockage.

[0004] Through multi-beam antennas, base stations can achieve spatial multiplexing, generate independent beams for different user directions, and greatly improve spectral efficiency at the same time. Due to its advantages such as wide coverage, it has been successfully applied in fields such as satellite communication and radar. As a lightweight, low-cost, and easy-to-fabricate antenna, transmissive array antennas have received extensive attention in the millimeter-wave field in recent years. Through electromagnetic wave transmission regulation technology, it can not only achieve high-gain and low-loss beamforming, but also has flexible beam direction control capabilities. At the same time, circularly polarized antennas can achieve polarization in the horizontal and vertical directions. Compared with linearly polarized antennas, they have better multipath propagation characteristics and anti-interference capabilities. In wireless communication systems, circular polarization technology can improve the transmission quality and coverage of signals, reduce signal attenuation and multipath effects. In summary, multi-beam transmissive array antennas with circular polarization, high gain, and wide beam coverage are an important research direction for millimeter-wave communication and satellite communication. Summary of the Invention

[0005] In view of the above deficiencies in the prior art, the present invention proposes a broadband circularly polarized multi-beam transmissive array antenna based on an SIW feeding network, which can achieve ±30° beam coverage.

[0006] To achieve the above-mentioned invention objectives, the present invention adopts the following technical solutions: A broadband circularly polarized multi-beam transmissive array antenna based on an SIW feeding network, comprising an adjustable phase polarization converter and a multi-beam circularly polarized feed source arranged vertically; the adjustable phase polarization converter includes a plurality of receiving and re-transmitting units arranged periodically; the receiving and re-transmitting unit includes an upper metal patch layer, an upper dielectric substrate layer, an intermediate metal ground layer, an adhesive layer, a lower dielectric substrate layer, a lower metal patch layer and metal vias stacked in sequence from top to bottom; the multi-beam circularly polarized feed source includes 5 circularly polarized feed sources arranged in a straight line, and the circularly polarized feed source includes a 4×4 metasurface unit, an SIW upper dielectric substrate layer, an SIW upper metal wall, an SIW lower dielectric substrate layer and an SIW lower metal wall stacked in sequence from top to bottom; the circularly polarized feed source outputs a right-handed circularly polarized electromagnetic wave, which is incident on the lower metal patch layer of a plurality of receiving and re-transmitting units of the adjustable phase polarization converter and is transmitted to the upper metal patch layer through the metal vias.

[0007] Further, as a preferred technical solution of the present invention, the multi-beam transmissive array antenna controls 360° phase compensation by rotating the periodically arranged upper metal patch layer. Under the incidence of right-handed circularly polarized waves, rotating the upper metal patch realizes 360° phase coverage while not changing the transmission amplitude, and forms a high-gain ±30° beam coverage in the far field.

[0008] Further, as a preferred technical solution of the present invention, a circular slit is etched at the geometric center of the intermediate metal ground layer, and the metal via passes through the circular slit to connect the upper metal patch layer and the lower metal patch layer.

[0009] Further, as a preferred technical solution of the present invention, the upper metal patch layer is circular and etched with an open square ring and diagonal rectangular slits, and can emit left-handed circularly polarized waves; the lower metal patch layer is circular and etched with an open square ring and diagonal rectangular slits, and can receive right-handed circularly polarized waves.

[0010] Further, as a preferred technical solution of the present invention, the 4×4 metasurface unit is a square patch with a sector slot cut off diagonally to excite circularly polarized waves.

[0011] Further, as a preferred technical solution of the present invention, the SIW upper metal wall is etched with a long slit at the center to realize energy transmission.

[0012] Further, as a preferred technical solution of the present invention, the SIW lower metal wall is etched with a pair of symmetric slits to realize the conversion from a grounded coplanar waveguide GCPW to an SIW. It is connected to an external adapter by GCPW and fed to the 4×4 metasurface unit after the GCPW-to-SIW conversion.

[0013] The broadband circularly polarized multi-beam transmissive array antenna based on the SIW feeding network described in the present invention, compared with the prior art by adopting the above technical solution, has the following technical effects:

[0014] (1) The multi-beam circularly polarized feed source proposed by the present invention has a relatively wide impedance bandwidth and axial ratio bandwidth.

[0015] (2) The adjustable-phase polarization conversion surface unit proposed by the present invention can achieve 360° phase adjustment without changing the transmission amplitude by rotating the upper metal patch layer, and can achieve linear phase within a relatively wide frequency band.

[0016] (3) The broadband circularly polarized multi-beam transmissive array antenna based on the SIW feeding network proposed by the present invention includes 5 beams, generates 5 pencil beams, and covers the range between ±30°.

[0017] (4) The broadband circularly polarized multi-beam transmissive array antenna based on the SIW feeding network proposed by the present invention has fewer layers, a simple structure, is easy to process, and has a lower cost. Description of the Drawings

[0018] Figure 1 is a three-dimensional structural schematic diagram of the antenna in the embodiment of the present invention;

[0019] Figure 2 is a side view of the antenna in the embodiment of the present invention;

[0020] Figure 3 is a top view of the adjustable-phase polarization conversion surface of the antenna in the embodiment of the present invention;

[0021] Figure 4 is a three-dimensional structural schematic diagram of the receiving and re-transmitting unit of the antenna in the embodiment of the present invention;

[0022] Figure 5 is the (a) top view of the upper metal patch layer, (b) top view of the middle metal ground layer, and (c) top view of the lower metal patch layer of the antenna in the embodiment of the present invention;

[0023] Figure 6 is a top view of the multi-beam circularly polarized feed source surface of the antenna in the embodiment of the present invention;

[0024] Figure 7 is a three-dimensional structural schematic diagram of the circularly polarized feed source of the antenna in the embodiment of the present invention;

[0025] Figure 8 is the (a) top view of the 4×4 metasurface unit, (b) top view of the upper SIW metal wall, and (c) top view of the lower SIW metal wall of the antenna in the embodiment of the present invention;

[0026] Figure 9is the (a)t of the receiving and re - transmitting unit of the antenna in the embodiment of the present invention xx 、t yy transmission coefficient and phase response performance diagram and (b)t xy 、t yx transmission coefficient and phase response performance diagram;

[0027] Figure 10 is the radiation pattern of the circularly - polarized feed port3 of the antenna in the embodiment of the present invention;

[0028] Figure 11 is the (a) reflection coefficient and (b) coupling coefficient performance diagrams of the circularly - polarized feed of the antenna in the embodiment of the present invention;

[0029] Figure 12 is the axial ratio versus frequency performance diagram of the circularly - polarized feed of the antenna in the embodiment of the present invention;

[0030] Figure 13 are the radiation patterns of 5 beams of the antenna in the embodiment of the present invention;

[0031] Figure 14 is the gain and axial ratio versus frequency performance diagram of port3 of the antenna in the embodiment of the present invention;

[0032] In the drawings, 1 - receiving and re - transmitting unit; 2 - upper metal patch layer; 3 - upper dielectric substrate layer; 4 - intermediate metal ground layer; 5 - adhesive layer; 6 - lower dielectric substrate layer; 7 - lower metal patch layer; 8 - metal via; 9 - circularly - polarized feed; 10 - 4×4 metasurface unit; 11 - SIW upper dielectric substrate layer; 12 - SIW upper metal wall, 13 - SIW lower dielectric substrate layer, 14 - SIW lower metal wall. Detailed implementation manners

[0033] The following will further explain the present invention in detail with reference to the drawings, so that those skilled in the art can understand the present invention more deeply and be able to implement it. However, the following is only for explaining the present invention by reference to examples and does not limit the present invention.

[0034] Such as Figure 1-8As shown in the figure, a broadband circularly polarized multi-beam transmissive array antenna based on an SIW feeding network includes an adjustable phase polarization converter and a multi-beam circularly polarized feed source arranged vertically; the adjustable phase polarization converter includes a plurality of receiving and re-transmitting units 1 arranged periodically; the receiving and re-transmitting unit 1 includes an upper metal patch layer 2, an upper dielectric substrate layer 3, an intermediate metal ground layer 4, an adhesive layer 5, a lower dielectric substrate layer 6, a lower metal patch layer 7 and metal vias 8 stacked in sequence from top to bottom; the multi-beam circularly polarized feed source includes 5 circularly polarized feed sources 9 arranged linearly, and the circularly polarized feed source 9 includes a 4×4 metasurface unit 10, an SIW upper dielectric substrate layer 11, an SIW upper metal wall 12, an SIW lower dielectric substrate layer 13 and an SIW lower metal wall 14 stacked in sequence from top to bottom.

[0035] As Figure 2 shown, the multi-beam feed source outputs a right-handed circularly polarized electromagnetic wave, which is incident on the lower surface of the adjustable phase polarization converter. Due to the polarization selection and polarization conversion characteristics of the adjustable phase polarization converter, the right-handed circularly polarized electromagnetic wave is received by the lower metal patch layer 7, transmitted through the metal vias 8 to the upper metal patch layer 2, twisted into a left-handed circularly polarized electromagnetic wave, and after obtaining the corresponding phase compensation, a high-gain beam coverage is formed in the far field region.

[0036] The parameters of the antenna in this embodiment are shown in the following table:

[0037] Parameter p <![CDATA[r1]]> <![CDATA[h1]]> <![CDATA[h2]]> <![CDATA[d1]]> <![CDATA[d2]]> <![CDATA[a1]]> <![CDATA[a2]]> <![CDATA[a3]]> Value (mm) 5.3 1.4 0.762 0.1 0.3 0.6 1.2 1 0.7 Parameter s <![CDATA[w1]]> <![CDATA[l1]]> <![CDATA[r a > sub_a sub_b <![CDATA[f m > <![CDATA[f x > <![CDATA[f y > Value (mm) 0.43 0.3 0.55 0.6 1.7 0.1 1 4.4 0.8 Parameter siw_w <![CDATA[h3]]> tapl_1 tapl_2 tapw_1 tapw_2 wg g rr Value (mm) 4.8 0.508 2.8 2.6 0.4 1.4 0.7 0.1 0.15

[0038] For the receiving and re-transmitting unit, p is the side length of the dielectric substrate, r1 is the radius of the circular metal patch, h1 is the height of the dielectric substrate, h2 is the height of the adhesive layer, d1 is the diameter of the metal via, d2 is the diameter of the circular gap in the floor layer, a1 is the outer side length of the open square ring, a2 is the inner side length of the open square ring, a3 is the opening length of the open square ring, s is the distance that the metal patch offsets in the xoy direction relative to the metal via, w1 is the width of the diagonal extended gap of the open square ring, and l1 is the length of the diagonal extended gap of the open square ring. For the circularly polarized feed source, r a is the radius of the sector, sub_a is the side length of the 4×4 super surface unit, sub_b is the distance between the 4×4 super surface units, f m is the distance between the center of the rectangular slot and the center of the SIW column, f x is the width of the rectangular slot, f yis the length of the rectangular slot, siw_w is the width of the SIW column, h3 is the thickness of the dielectric substrate, tapl_1 is the height of the trapezoidal groove on the lower metal wall of the SIW, tapl_2 is the length of the slot strip on the lower metal wall of the SIW, tapw_1 is the bottom length of the trapezoidal groove on the lower metal wall of the SIW, tapw_2 is the top length of the trapezoidal groove on the lower metal wall of the SIW, wg is the distance between the two slot strips on the lower metal wall of the SIW, g is the width of the slot strip, and rr is the radius of the SIW column.

[0039] As Figure 4 shown, the upper dielectric substrate layer 3 and the lower dielectric substrate layer 6 of the receive and re-transmit unit 1 are the same in material and size, with a relative permittivity εr of [2.2, 6.2], a loss tangent tanδ of 0.0009, a height h1 of [0.02λ, 0.1λ], and the relative permittivity ε r of the adhesive layer 5 is 3.5, the loss tangent tanδ is 0.004, and the height is h2. The metal through-hole 8 is made of pec. In addition, the relative permittivity ε r of the circularly polarized feed is [2.2, 6.2], the loss tangent tanδ is 0.0009, and the height h1 is [0.02λ, 0.1λ], where λ is the free-space wavelength.

[0040] As Figure 5 (a) and (c) shown, the xoy plane of the receive and re-transmit unit 1 is a square structure with a side length p of [0.2λ, λ], and the radius r1 of the circular metal patch on its surface is [0.1λ, 0.5λ]. The lower metal patch layer 7 has the same structure as the upper metal patch layer 2.

[0041] As Figure 5 (b) shown, the middle metal ground layer 4 of the receive and re-transmit unit 1 is a square structure with a side length of p, and a metal through-hole 8 with a diameter d1 of [0.03λ, 0.06λ] passes through the center of its surface, and a circular slot with a diameter d2 of [0.06λ, 0.1λ] is etched at the center, so that the metal through-hole 8 can pass through and connect the upper and lower metal patches.

[0042] As Figure 7 shown, the SIW upper dielectric substrate layer 11 and the SIW lower dielectric substrate layer 13 of the circularly polarized feed 9 are the same in material and size, with a relative permittivity εr of [2.2, 6.2], a loss tangent tanδ of 0.0009, and a height h3 of [0.02λ, 0.1λ].

[0043] As Figure 9 (a) shown, the coefficient and phase change of the receive and re-transmit unit 1 within the frequency range are such that t xx and t yy at a frequency of 29.5 GHz, the amplitudes are equal and both are -6 dB, and t xx -t yy= 180°; As Figure 9 (b) shows that t xy and t yx At a frequency of 29.5 GHz, the amplitudes are equal, both -6 dB, and the phases are equal.

[0044] As Figure 10 shown, the circularly polarized feed 9 has a peak gain of 8 dB at the center frequency of 28 GHz and has a symmetric and stable radiation pattern in the E-plane and H-plane.

[0045] As Figure 11 shown, in the range of 22 - 34 GHz, the reflection coefficient of the circularly polarized feed 9 is less than -10 dB, and the coupling coefficient is less than -20 dB.

[0046] As Figure 12 shown, in the range of 27 - 32 GHz, the circularly polarized feed 9 has a 3 dB axial ratio bandwidth of 17%.

[0047] As Figure 13 shown, the broadband circularly polarized multi-beam transmissive array antenna based on the SIW feed network generates 5 pencil beams, which are respectively directed to the directions of -30°, -15°, 0°, 15° and 30°, and can achieve ±30° beam coverage. At 28 GHz, the beam peak gains are 18.5 dBi, 21.4 dBi, 21.7 dBi, 21.2 dBi and 18.8 dBi respectively, and the corresponding aperture efficiencies are 12%, 18.6%, 25.1%, 17.8% and 12.9% respectively. The beam scanning loss of the 5 beams is 3.2 dB.

[0048] As Figure 14 shown, in the frequency range of 25.5 - 30.5 GHz, the antenna has a 3 dB gain bandwidth of 17.9%, and in the frequency range of 24.8 - 32 GHz, the antenna has an axial ratio bandwidth of 25.4%.

[0049] The specific implementation schemes described above further elaborate on the purpose, technical solutions and beneficial effects of the present invention. It should be understood that the above are only specific implementation schemes of the present invention and are not intended to limit the scope of the present invention. Any equivalent changes and modifications made by those skilled in the art without departing from the concept and principles of the present invention shall fall within the scope of protection of the present invention.

Claims

1. A broadband circularly polarized multi-beam transmissive array antenna based on an SIW feed network, characterized in that It includes an adjustable phase polarization converter and a multi-beam circular polarization feed arranged vertically; the adjustable phase polarization converter includes a plurality of receiving and retransmitting units (1) arranged periodically; the receiving and retransmitting unit (1) includes an upper metal patch layer (2), an upper dielectric substrate layer (3), an intermediate metal ground layer (4), an adhesive layer (5), a lower dielectric substrate layer (6), a lower metal patch layer (7) and metal vias (8) stacked in sequence from top to bottom; the multi-beam circular polarization feed includes 5 circular polarization feeds (9) arranged in a straight line, and the circular polarization feed (9) includes a 4×4 metasurface unit (10), an SIW upper dielectric substrate layer (11), an SIW upper metal wall (12), an SIW lower dielectric substrate layer (13) and an SIW lower metal wall (14) stacked in sequence from top to bottom; the circular polarization feed (9) outputs a right-handed circularly polarized electromagnetic wave, which is incident on the lower metal patch layer (7) of a plurality of receiving and retransmitting units (1) of the adjustable phase polarization converter, and is transmitted to the upper metal patch layer (2) through the metal vias (8).

2. The broadband circularly polarized multi-beam transmissive array antenna based on the SIW feed network according to claim 1, wherein The multi-beam transmissive array antenna controls 360° phase compensation by rotating the periodically arranged upper metal patch layer (2). Under the incidence of right-handed circularly polarized waves, rotating the upper metal patch realizes 360° phase coverage while not changing the transmission amplitude, and forms a high-gain ±30° beam coverage in the far field region.

3. The broadband circularly polarized multi-beam transmissive array antenna based on the SIW feed network according to claim 1, wherein A circular slit is etched at the geometric center of the intermediate metal ground layer (4), and the metal via (8) passes through the circular slit to connect the upper metal patch layer (2) and the lower metal patch layer (7).

4. The broadband circularly polarized multi-beam transmissive array antenna based on the SIW feeding network according to claim 3, wherein The upper metal patch layer (2) is circular and etched with an open square ring and diagonal rectangular slits, and can emit left-handed circularly polarized waves; The lower metal patch layer (7) is circular and etched with an open square ring and diagonal rectangular slits, and can receive right-handed circularly polarized waves.

5. The broadband circularly polarized multi-beam transmissive array antenna based on the SIW feeding network according to claim 1, wherein The 4×4 metasurface unit (10) is a square patch with a sector-shaped groove cut off diagonally, which is used to excite circularly polarized waves.

6. The broadband circularly polarized multi-beam transmissive array antenna based on the SIW feeding network according to claim 1, wherein The SIW upper metal wall (12) etches a long slit at the center to realize energy transmission.

7. The broadband circularly polarized multi-beam transmissive array antenna based on the SIW feeding network according to claim 1, wherein The SIW lower metal wall (14) etches a pair of symmetric slits to realize the conversion from a grounded coplanar waveguide GCPW to SIW, and is connected to an external adapter by GCPW, and is fed to the 4×4 metasurface unit (10) after the GCPW-to-SIW conversion.

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