CN114744409A - Ten-fold frequency-range dual-polarized strong-coupling phased array antenna loaded by resistive material - Google Patents

Abstract

The invention discloses a ten-fold frequency-range dual-polarized strong-coupling phased array antenna loaded by resistive materials, which comprises a double-layer super-material wide-angle impedance matching layer, a strong-coupling dipole, a feed balun, an interdigital resistive frequency selection surface, a feed impedance gradient layer and an array edge resonance circuit. The dipole and the feed balun are integrated into a whole, a double-layer metamaterial wide-angle impedance matching layer is loaded at the top, an interdigital resistive frequency selection surface is loaded at the lower part of the dipole and the feed balun simultaneously, and the main body of the dipole is in a hollow square ring shape; the array edge is loaded with an array edge resonant circuit which is composed of a lumped resistor, a lumped capacitor and a lumped inductor. According to the invention, by loading the double-layer metamaterial wide-angle impedance matching layer, the interdigital resistive frequency selection surface and the array edge resonance circuit, the improvement on the performance of the unit and the array is realized, and the physical characteristics of low section and modularization and excellent radiation performances such as ultra wide band and wide scanning angle are achieved.

Description

A Decade Dual-Polarized Strongly Coupled Phased Array Antenna Loaded with Resistive Materials

technical field

The invention belongs to the technical field of antenna engineering, and in particular relates to a ten-octave frequency band dual-polarization strong coupling phased array antenna loaded with resistive materials.

Background technique

The antenna is the most front-end and key component in the wireless system. It mainly plays the role of energy conversion between guided waves and electromagnetic waves in free space, so it can transmit and receive electromagnetic waves. Among many antenna systems, phased array antennas are widely used in the fields of radar, communication and electronic countermeasures due to their rapid beam change capability, multi-beam scanning capability, and space signal power synthesis capability. Phased array antennas use active solid-state transceiver components to electronically control the excitation amplitude and phase of each antenna unit. At present, the increasingly mature electronic control technology enables phased array antennas to achieve fast beam scanning, comprehensive beamforming, high-precision tracking and Advanced electronic communication functions such as adaptive anti-jamming. In order to further improve the signal resolution and data transmission capacity in wireless communication, phased array antennas with ultra-wide operating frequency bands have become an inevitable development trend. At the same time, multi-functional systems require radar antenna equipment to be miniaturized, integrated and low Cost reduction to meet the strategic needs of mass production and adapt to the more complex strategic environment in the future. Therefore, it is necessary to seek a systematic design idea for ultra-wideband phased array antennas and build phased arrays with broadband impedance matching, high integration and miniaturization. Array antennas are of vital importance to future civilian communication systems and multi-functional military platforms.

Based on the above requirements, an antenna form that strengthens the coupling between array elements and makes use of them, that is, a strong coupling antenna emerges as the times require. Through strong capacitive coupling between units, this antenna not only reduces the horizontal and vertical dimensions of the unit, but also achieves wider bandwidth characteristics than traditional broadband antennas. At the same time, on the basis of the strong coupling unit, the loading of the new metamaterial further improves the performance of the antenna in all aspects. For example, the Chinese patent with the application number of CN202010161851.X "Strongly coupled ultra-wideband phased array antenna based on interdigital resistive surface loading" proposes loading an interdigitated resistive surface, which can broaden the working frequency band of the antenna, but the antenna's Although the wide-angle impedance matching layer adopts a metamaterial structure, it is still too thick, which is not conducive to the practical application of the antenna. In the Chinese patent with the application number CN 202011240737.2 "Ultra-low-profile and low-scattering ultra-wideband phased array based on electromagnetic metamaterial loading", the metamaterial surface plays a role in significantly reducing the cross-polarization RCS of the phased array antenna itself, improving the The stealth performance is improved, but the antenna bandwidth is limited. In the article "Dual-Linear Polarized Phased Array with 9:1 Bandwidth and 60° Scanning off Broadside" published in the top journal IEEE Transactionson Antenna and Propagation in the field of antennas in 2019, the author uses a strongly coupled antenna to achieve a 9-octave ultra-wideband. band, but its antenna performance is poor when the H-plane is scanned at a large angle.

The above-mentioned patents and articles have all contributed to the strong coupling antenna form and metamaterial loading. Therefore, there is still room for great improvement in the antenna performance. It is of great practical engineering significance to study this novel antenna structure to obtain higher performance antenna specifications.

SUMMARY OF THE INVENTION

In view of the deficiencies in the prior art, the ten-octave-band dual-polarization strongly coupled phased array antenna loaded with resistive materials provided by the present invention solves the problems of the existing phased array antennas, such as narrow antenna bandwidth, high profile and scanning Small angle problem.

In order to achieve the above purpose of the invention, the technical solution adopted in the present invention is as follows: a decade-octave dual-polarized strong coupling phased array antenna loaded with resistive materials, comprising a double-layer metamaterial wide-angle impedance matching layer (1), a strong A coupled dipole and feed balun (2), an interdigitated resistive frequency selective surface (3), a feed impedance graded layer (4), and an array edge resonant circuit (5).

The double-layer metamaterial wide-angle impedance matching layer (1) is divided into an upper-layer elliptical split-ring structure (101) and a lower-layer concentric circular split-ring structure (102), which are respectively printed on both sides of a dielectric substrate with a thickness of 3 mm and a dielectric constant of 2.2 The upper layer elliptical split ring structure (101) improves the E-plane scanning performance of the antenna in the dual polarization direction by enhancing the current coupling of the horizontal and vertical polarization directions; the lower layer concentric split ring structure (102) improves the horizontal and vertical The H-plane current coupling in the polarization direction improves the H-plane scanning performance of the antenna in dual polarization directions.

Further, the strongly coupled dipole and the feeding balun (2) are integrated into the same dielectric substrate, and include a horizontal polarization unit (201), a vertical polarization unit (202) and a feeding balun (203), Slots are made at the ends of the horizontal polarization unit (201) and the vertical polarization unit (202) to enable them to be inserted into each other. At the same time, the ends of the dipoles are provided with ground branches to eliminate common mode resonance that may occur in the band; The electric balun (203) adopts a double Y-type balun, which realizes the transformation from the unbalanced feeding provided by the coaxial joint to the balanced feeding, and undertakes part of the impedance transformation function.

Further, the feed impedance gradient layer (4) comprises a horizontal polarization gradient line (401), a vertical polarization gradient line (402) and a balun ground patch (403), wherein the horizontal polarization gradient line (401) ) and the vertical polarization gradient line (402) need to be electrically connected to the front feed line of the feed balun (203), and the balun ground patch (403) needs to be connected to the back ground plate of the feed balun (203). electrical connection;

Further, the interdigitated resistive frequency selection surface (3) adopts a special plate, the surface is covered with a resistive material with a square resistance of 50Ω/square, the main body is configured as a hollow square ring, and each antenna unit includes 4 square rings, An interdigitated structure is designed at the intersection of the square ring to enhance the capacitive coupling component, so that the interdigitated resistive frequency selective surface (3) can absorb electromagnetic waves of a specific frequency while having frequency selectivity, thereby greatly improving the electrical performance of the antenna.

Further, in order to realize the actual phased array function, the antenna unit needs to form a finite array of a certain scale to work in the application, and a low-frequency destructive resonance will be generated at the edge of the array due to the truncation effect, and the array edge resonant circuit ( 5) Use lumped resistance (501), lumped capacitance (502) and lumped inductance (503) to form a grounded RLC resonant circuit, and set it at the left and right edges of the designed finite array, and use the frequency selection of the RLC resonant circuit For the specific frequency standing wave resonance point caused by the surface wave caused by the edge truncation effect, the effective selective absorption is carried out, the destructive resonance is eliminated, and the standing wave performance of the edge port of the finite array is greatly improved.

The beneficial effects of the present invention are as follows: the ten-octave-band dual-polarized strong-coupling phased array antenna loaded by the resistive material provided by the present invention first successfully applies the working principle of the strong-coupling array, and realizes it by the enhancement of the capacitive coupling at the end of the dipole. The ultra-wide bandwidth of the ten-octave band is achieved; secondly, a new double-layer metamaterial wide-angle impedance matching layer is used, and the upper and lower layers are respectively provided with special structures for the scanning performance of the E surface and the H surface, which greatly improves the scanning performance; The interdigital resistive frequency selective surface is loaded between the ground and the floor, which improves the voltage standing wave ratio in the whole frequency band; and considers the truncation effect produced by the edge of the finite actual array, an RLC resonant circuit is designed to eliminate the destructive resonance. The above measures make the antenna meet the requirements of ultra-wide frequency band, low profile and wide scanning angle, give full play to the broadband advantage of strong coupling array and the superior performance of metamaterial structure, and have more practical engineering application value.

Description of drawings

FIG. 1 is a schematic structural diagram of a decade-band dual-polarization strongly coupled phased array antenna unit loaded with resistive materials provided by the present invention.

FIG. 2 is a one-dimensional four-element array of a decade-band dual-polarized strongly coupled phased array antenna loaded with resistive materials provided by the present invention, which is used to verify the effectiveness of edge processing measures.

FIG. 3 is a schematic structural diagram of a double-layer metamaterial wide-angle impedance matching layer in an embodiment provided by the present invention.

4 is a schematic diagram of an interdigitated resistive frequency selective surface structure in an embodiment provided by the present invention.

FIG. 5 is a schematic diagram of a feeding impedance gradient layer in an embodiment provided by the present invention.

FIG. 6 is a situation of scanning standing waves at 0-45 degrees on the E-plane and the H-plane of the horizontally polarized port of a dual-polarization unit according to an embodiment provided by the present invention (as shown in FIG. 1 ).

FIG. 7 is an embodiment of the present invention (as shown in FIG. 1 ) showing the variation of the actual gain of the horizontally polarized port E-plane and H-plane of the dual-polarization unit 0-45 degree scanning with frequency.

FIG. 8 is a directional diagram of 0 degree and 45 degree main polarization and cross polarization at 2 GHz after the units form a 6×8 area array in the embodiment provided by the present invention.

FIG. 9 is a directional diagram of 0-degree, 45-degree main polarization and cross polarization at 1 GHz after the units form a 6×8 area array in the embodiment provided by the present invention.

FIG. 10 is a directional diagram of 0 degree and 45 degree main polarization and cross polarization at 0.2 GHz after the units form a 6×8 area array in the embodiment provided by the present invention.

Fig. 11 is a comparison of the standing wave at the port with no special treatment at the edge and after adding the special treatment of the RLC resonant circuit after the cells are formed into a finite array in the embodiment provided by the present invention (as shown in Fig. 1).

Among them: 1. Double-layer metamaterial wide-angle impedance matching layer; 2. Strong coupling dipole and feeding balun; 3. Interdigital resistive frequency selective surface; 4. Feeding impedance gradient layer; 5. Array edge Resonant circuit; 101, upper elliptical split ring structure; 102, lower concentric circular split ring structure; 201, horizontal polarization unit; 202, vertical polarization unit; 203, feeding balun; 401, horizontal polarization gradient line; 402 , vertical polarization gradient line; 403, balun ground patch; 501, lumped resistance; 502, lumped capacitance; 503, lumped inductance.

Detailed ways

The specific embodiments of the present invention are described below to facilitate those skilled in the art to understand the present invention, but it should be clear that the present invention is not limited to the scope of the specific embodiments. For those skilled in the art, as long as various changes Such changes are obvious within the spirit and scope of the present invention as defined and determined by the appended claims, and all inventions and creations utilizing the inventive concept are within the scope of protection.

As shown in Figure 1, a ten-octave-band dual-polarized strongly coupled phased array antenna loaded with resistive materials includes a double-layer metamaterial wide-angle impedance matching layer (1), a strongly coupled dipole and a feeding bar Lun (2), an interdigitated resistive frequency selection surface (3), and a feeding impedance gradient layer (4). The strongly coupled dipole and the feeding balun (2) are integrally integrated on the same dielectric substrate, and include a horizontal polarization unit (201), a vertical polarization unit (202), and a feeding balun (203). The ends of the polarization unit (201) and the vertical polarization unit (202) are slotted so that they can be inserted into each other. At the same time, the end of the dipole is provided with a ground branch to eliminate common mode resonance that may occur in the band; the feeding balun (203) By adopting double Y-type baluns, the transformation from the unbalanced feed provided by the coaxial joint to the balanced feed is realized, and part of the impedance transformation function is undertaken;

As shown in Fig. 2, for the array edge resonant circuit (5) loaded by a finite array, a grounded RLC resonant circuit is constructed using a lumped resistance (501), a lumped capacitance (502) and a lumped inductance (503), and the Set at the left and right edges of the designed finite array, using the frequency selectivity of the RLC resonant circuit, for the specific frequency standing wave resonance point brought by the surface wave caused by the edge truncation effect, it can effectively selectively absorb and eliminate the destructive resonance, greatly improving the standing wave performance of the edge port of the finite array.

As shown in Figure 3, the double-layer metamaterial wide-angle impedance matching layer (1) is divided into an upper elliptical split ring structure (101) and a lower concentric circular split ring structure (102), which are respectively printed on a thickness of 3 mm and a dielectric constant of 3 mm. 2.2 on both sides of the dielectric substrate; the upper layer elliptical split ring structure (101) improves the E-plane scanning performance of the antenna in the dual polarization direction by enhancing the current coupling of the horizontal and vertical polarization directions; the lower layer concentric circular split ring structure (102) ) By enhancing the H-plane current coupling in the horizontal and vertical polarization directions, the H-plane scanning performance of the antenna in the dual-polarization direction is improved; due to the large aperture of the 6X8 actual array, the double-layer metamaterial wide-angle impedance matching layer (1) can be It is divided into left and right parts for processing, and then spliced.

As shown in Figure 4, the interdigitated resistive frequency selection surface (3) is made of a special plate, the surface is covered with a resistive material with a square resistance of 50Ω/square, the main body is structured as a hollow square ring, and each antenna unit contains 4 A square ring, and an interdigitated structure is designed at the junction of the square ring to enhance the capacitive coupling component, so that the interdigitated resistive frequency selective surface (3) can absorb electromagnetic waves of a specific frequency while having frequency selectivity, which greatly improves the antenna. At the same time, in order to make the strongly coupled dipole and feeding balun (2) pass through the interdigital resistive frequency selective surface (3) and feed smoothly, it is necessary to connect the interdigitated resistive frequency selective surface ( 3) Cut out an escape groove and a corresponding positioning hole for support.

As shown in FIG. 5 , the feed impedance gradient layer (4) includes a horizontal polarization gradient line (401), a vertical polarization gradient line (402) and a balun ground patch (403). The function of the gradient line is to transform the impedance of 50Ω at the coaxial joint into about 90Ω, which relieves the pressure of the feeding balun (203) to realize impedance transformation. Wherein, both the horizontal polarization gradient line (401) and the vertical polarization gradient line (402) need to be electrically connected to the front feeding line of the feeding balun (203), and the balun grounding patch (403) is provided with metallization The via hole is electrically connected to the back floor, and then electrically connected to the back ground plate of the feeding balun (203) to realize the grounding of the feeding balun (203). 2) For vertical fixing, there is a slot slightly wider than the base plate of the feeding balun (203) next to the balun grounding patch (403) for insertion and welding.

It should be noted that if the high-frequency element array element spacing is equal to the half-wavelength of its highest frequency, no grating lobes will be generated when scanning to any angle (except ±90 degrees) in the entire operating frequency band. In order to ensure the antenna performance as much as possible, the radiation aperture of the antenna is not reduced to achieve greater gain. Therefore, in the present invention, the overall height of the phased array antenna is 0.63 wavelengths of the highest frequency in the frequency band, and the distance between adjacent dipole units is 0.44 wavelengths of the highest frequency in the frequency band.

Fig. 6 shows the corresponding standing wave characteristics of the ports of the present embodiment in different scanning states of the E-plane and the H-plane. It can be seen from the figure that within the scanning range of 45 degrees, the present embodiment has an impedance bandwidth of 10:1, and The voltage standing wave ratio is less than 2.8. (Because the two ports of this dual-polarized antenna are completely symmetrical in structure, the following illustrations only show the case of one of the ports)

Figure 7 shows the main polarization and cross-polarization characteristics corresponding to all frequencies of the ports in different scanning states of the E and H planes of this embodiment. It can be seen from the figure that the antenna of this embodiment has normal gain in the whole frequency band, and no Distortion points appear, and the cross-polarization performance in the entire working frequency band can be below -15dB, which is better than most strongly coupled antennas.

FIG. 8 shows the main polarization and cross-polarization of the 6×8 area array provided by the present embodiment in the case of 0-degree and 45-degree scanning at the 2GHz frequency point. It can be seen from the figure that the main polarization of the antenna array in this embodiment can reach 20dB at 2GHz, the main and side lobe ratio can reach more than 13dB, and the beam pointing is accurate during scanning.

FIG. 9 shows the main polarization and cross-polarization of the 6×8 area array provided in this embodiment in the case of scanning 0 degrees and 45 degrees at the 1 GHz frequency point. It can be seen from the figure that the main polarization of the antenna array in this embodiment can reach 15dB at 1GHz, the main and side lobe ratio can reach more than 13dB, and the beam pointing is accurate during scanning.

Figure 10 shows the main polarization and cross-polarization of the 6X8 area array provided by this embodiment, in the case of 0-degree and 45-degree scanning at the 0.2GHz frequency point, and also has good cross-polarization characteristics and beams Scan characteristics.

Figure 11 shows the effect brought by the array edge resonant circuit provided in this embodiment. Taking a four-element semi-infinite array as a simulation example, the above figure shows the port standing wave when the edge resonant circuit is not loaded. It can be seen that No. 1 The port (that is, the most edge port) produces a destructive resonance at 0.4GHz, which greatly affects the performance of the array; the figure below shows the standing wave of the port when the edge resonant circuit is loaded. It can be seen that the destructive resonance is eliminated, which proves that the edge treatment the effectiveness of the measures.

Claims (4)

1. a decade-octave dual-polarization strong coupling phased array antenna loaded with resistive material, is characterized in that, comprises double-layer metamaterial wide-angle impedance matching layer (1), strong coupling dipole and feeding bar Lun (2), interdigital resistive frequency selective surface (3), feeding impedance graded layer (4) and array edge resonant circuit (5); the strongly coupled dipole and feeding balun (2) are integrated Integrated on the same dielectric substrate, including a horizontal polarization unit (201), a vertical polarization unit (202), and a feeding balun (203), and opening at the ends of the horizontal polarization unit (201) and the vertical polarization unit (202) slot, so that it can be inserted, and the lower part is welded with the feeding impedance gradient layer (4) to ensure electrical connection; the feeding impedance gradient layer (4) includes a horizontal polarization gradient line (401), a vertical polarization gradient line ( 402) and the balun ground patch (403). 2. The ten-octave dual-polarization strong coupling phased array antenna loaded by resistive material according to claim 1, is characterized in that, described double-layer metamaterial wide-angle impedance matching layer (1) is divided into upper layer ellipse The split ring structure (101) and the lower concentric circular split ring structure (102); the upper elliptical split ring structure (101) improves the E-plane scanning of the antenna in the dual-polarization direction by enhancing the current coupling of the E-plane in the horizontal and vertical polarization directions performance; the lower concentric circular split ring structure (102) improves the H-plane scanning performance of the antenna in dual polarization directions by enhancing the H-plane current coupling in the horizontal and vertical polarization directions. 3. The ten-octave dual-polarized strongly coupled phased array antenna loaded with resistive material according to claim 1, wherein the interdigital resistive frequency selective surface (3) adopts a square resistance of 50Ω. Resistive material, the main body is constructed as a hollow square ring, each antenna unit contains 4 square rings, and an interdigital structure is designed at the junction of the square rings to enhance the capacitive coupling component, so that the interdigital resistive frequency selection surface (3) is While having frequency selectivity, it can absorb electromagnetic waves of specific frequencies, greatly improving the electrical performance of the antenna. 4. The ten-octave dual-polarized strongly coupled phased array antenna loaded with resistive materials according to claim 1, wherein the array edge resonant circuit (5) uses a lumped resistance (501), a lumped The total capacitance (502) and the lumped inductance (503) constitute a grounded RLC resonant circuit, which is set at the left and right edges of the designed finite array. The frequency selectivity of the RLC resonant circuit is used to solve the problem of surface waves caused by the edge truncation effect. The specific frequency standing wave resonance point brought by it can be effectively selectively absorbed, which greatly improves the standing wave performance of the edge port of the finite array.

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