CN-115995673-B - Wide-angle frequency-scanning antenna based on dual-band coupling filter

CN115995673BCN 115995673 BCN115995673 BCN 115995673BCN-115995673-B

Abstract

The invention discloses a wide-angle frequency scanning antenna based on a dual-band coupling filter, which comprises a power divider module, a dual-band filter module and an antenna radiating unit. The power divider module is used for distributing power to input signals, the dual-band filter module is used for carrying out phase modulation on output signals of the power divider, and the antenna radiation unit is used for dual-band signal radiation. The invention adopts the dual-band filter to carry out phase modulation on signals, respectively realizes two groups of different phase distribution along with frequency variation in two designated frequency bands, respectively covers different positive and negative angle ranges, finally realizes wide-angle scanning of-60 DEG to 60 DEG, reduces the design pressure of a single-frequency scheme by the dual-frequency design, and can flexibly customize the frequency band range according to actual requirements by virtue of the flexible bandwidth design function of the filter. The wide-angle frequency scanning antenna has the advantages of large scanning range, small scanning gain fluctuation, customizable frequency band range and the like.

Inventors

GUO XIN
Huang Lanxin
WU WEN

Assignees

南京理工大学

Dates

Publication Date: 20260512
Application Date: 20230228

Claims (5)

1. The wide-angle frequency scanning antenna based on the dual-band coupling filter is characterized by comprising a power divider module, a dual-band filter module and an antenna radiation unit; the power divider module is used for dividing power of input signals; The dual-band filter module is used for carrying out phase modulation on the output signal of the power divider module, and respectively realizing two groups of different phase distributions which change along with the frequency in the appointed two frequency bands so as to realize the frequency scanning of the dual frequency bands; the antenna radiation unit is used for radiating signals in dual frequency bands; The power divider module, the dual-band filter module and the antenna radiating unit are sequentially connected by adopting a microstrip line or a coaxial line; the dual-band filter module comprises four independent dual-band substrate integrated waveguide filters, wherein the orders are 3, 4, 5 and 6, namely 3, 4, 5 and 6 resonant cavities; The signal input and output ports of the 3-order and 5-order dual-band substrate integrated waveguide filters are centrosymmetric and are used for generating-180 DEG phase shift in the second frequency band, and the signal input and output ports of the 4-order and 6-order dual-band substrate integrated waveguide filters are axisymmetric and are used for keeping the phase of the second frequency band unchanged; The 3-order, 4-order, 5-order and 6-order dual-band substrate integrated waveguide filter meets the following conditions: In the first frequency band, the phase at the center frequency is sequentially reduced by 90 degrees along with the increase of the order, the mode value of the phase slope is gradually increased, and the phase difference of adjacent filters is equal by adjusting the bandwidths of the dual-band substrate integrated waveguide filters; In the second frequency band, 3-order and 5-order ports are used to form central symmetry, so that the phase at the central frequency is sequentially increased by 90 degrees along with the increase of the order, the mode value of the phase slope is also increased, and the phase difference equality of adjacent filters is realized by adjusting the bandwidths of the dual-band substrate integrated waveguide filters.
2. The wideband filter-based wide-angle sweep antenna of claim 1, wherein the power divider module comprises four output ports, and performs signal power distribution according to a power ratio of 1:1.5:1.5:1, and outputs the signal power distribution to four dual-band substrate integrated waveguide filters respectively.
3. The wideband filter-based wide-angle sweep antenna of claim 2, wherein the power divider module is composed of one split-two wilkinson equal power divider and two identical split-two wilkinson unequal power dividers.
4. The wide-angle frequency scanning antenna based on the dual-band coupling filter according to claim 1, wherein the antenna radiating unit comprises four dual-frequency quasi-yagi antennas with side-by-side structures, and a wide beam is maintained in a required dual-frequency range, namely, a beam width in the dual-frequency range is maintained to be larger than a designed scanning angle range.
5. The dual band coupling filter based wide angle sweep antenna of claim 4 wherein adjacent dual band quasi-yagi antenna elements are equally spaced apart by a spacing d = 0.34 λ f1 /0.45λ f2 , where λ f1 and λ f2 are free space wavelengths of the first and second frequency bands, respectively.

Description

Wide-angle frequency-scanning antenna based on dual-band coupling filter Technical Field The invention belongs to the technical field of antennas, and particularly relates to a wide-angle frequency scanning antenna based on a dual-band coupling filter. Background The beam scanning antenna has a beam scanning function, and is widely applied to the fields of radar imaging, target detection, wireless communication and the like. The electric scanning antenna changes the phase difference between the antenna units through electric signals, so that the beam direction of the antenna array is controlled, and two common modes are phase scanning and frequency scanning. Compared with phase scanning, the beam of the frequency scanning antenna deflects along with the frequency change of an excitation signal, an additional phase shifter is not needed, and the frequency scanning antenna has the advantages of high cost performance, high beam forming speed and the like and is widely focused by people. Currently, the frequency scanning antenna is mainly realized by adopting a leaky wave antenna or introducing a slow wave line structure. The leaky-wave antenna has higher efficiency, but the traditional leaky-wave antenna can only realize forward single-side scanning, and has the problems of small scanning range, higher side lobe of a directional diagram, large scanning gain change and the like. The slow wave line structure has larger size and higher loss, and the loss gradually increases and becomes larger along with the increase of the array scale, so that the frequency scanning antenna has low efficiency and limited array scale. Therefore, the realization of a high-performance frequency-scanning antenna array with low passive cost, wide-angle scanning, low side lobe, high efficiency, high gain, small scanning gain variation and the like has become an important research point in recent years. Disclosure of Invention The invention aims to provide a wide-angle frequency-scanning antenna based on a dual-band coupling filter, which is passive, wide in scanning angle range, flat in gain variation and flexible in frequency band design. The technical scheme for realizing the purpose of the invention is that the wide-angle frequency scanning antenna based on the dual-band coupling filter comprises a power divider module, a dual-band filter module and an antenna radiation unit; the power divider module is used for dividing power of input signals. In particular, low side lobes can be achieved with unequal amplitude distribution. The dual-band filter module is used for carrying out phase modulation on the output signals of the power divider module, and respectively realizing two groups of different phase distributions which change along with the frequency in the appointed two frequency bands so as to realize the frequency scanning of the dual frequency bands. Particularly, the phase difference between adjacent antenna units under two frequency bands is opposite in polarity, so that different scanning angle coverage ranges are realized, and the scanning range is expanded by utilizing the two frequency bands. The antenna radiation unit is used for radiating signals in dual frequency bands; the power divider module, the dual-band filter module and the antenna radiating unit are sequentially connected by adopting microstrip lines or coaxial lines. Further, the dual-band filter module comprises four independent dual-band substrate integrated waveguide filters, wherein the orders are 3, 4, 5 and 6, namely, 3, 4, 5 and 6 resonant cavities. Further, the signal input and output ports of the 3-order and 5-order dual-band substrate integrated waveguide filters are centrosymmetric and are used for generating-180 DEG phase shift in the second frequency band, and the signal input and output ports of the 4-order and 6-order dual-band substrate integrated waveguide filters are axisymmetric and are used for keeping the phase of the second frequency band unchanged. Further, the 3-order, 4-order, 5-order and 6-order dual-band substrate integrated waveguide filter meets the following conditions that the phase is sequentially reduced by 90 degrees along with the increase of the order in a first frequency band, the modulus of the phase slope is gradually increased, the phase difference of adjacent filters is equal by adjusting the bandwidths of the filters, the 3-order and 5-order ports are used for forming central symmetry in a second frequency band, the phase is sequentially increased by 90 degrees along with the increase of the order in the center frequency band, the modulus of the phase slope is also increased along with the increase of the order, and the phase difference of the adjacent filters is equal by adjusting the bandwidths of the filters. Preferably, the four output ports of the power divider module perform signal power distribution according to a power ratio of 1:1.5:1.5:1. Preferably, the power divider module is composed of one-half wilkinson