CN-116937180-B - Large-spacing sparse phased array antenna based on low-profile Maxwell fisheye lens

Abstract

The invention discloses a large-space sparse phased array antenna based on a low-profile Maxwell fisheye lens, and belongs to the technical field of microwave antennas. The phased array antenna consists of periodically arranged lens antenna units, wherein each lens antenna unit comprises a Maxwell fisheye lens, a metal cavity and five microstrip patch antennas, and each Maxwell fisheye lens is of a cylindrical structure and is formed by concentrically nesting a plurality of layers of circular lenses with gradually increased radiuses from top to bottom. The phased array antenna has the sparseness reaching 72.4%, can realize scanning at + -43 degrees, has sidelobe level smaller than-7.4 dB, and can greatly reduce the cost of a phased array system, has gain loss smaller than 2dB, has zero-degree gain higher than the gain of the full array antenna, reduces the system cost and ensures the radiation characteristic of the array antenna.

Inventors

• DING XIAO
• Han Liuyuanzhi

Assignees

• 电子科技大学

Dates

Publication Date

20260505

Application Date

20230629

Claims (4)

1. 1. The large-spacing sparse phased array antenna based on the low-profile Maxwell fisheye lens comprises M multiplied by N lens antenna units which are arranged periodically, and is characterized in that the center distance between the lens antenna units is larger than the free space wavelength corresponding to the working center frequency; The lens antenna unit comprises a low-profile Maxwell fish-eye lens, a metal cavity and five microstrip patch antennas; The low-profile Maxwell fisheye lens is of a cylindrical structure and is formed by concentrically nesting K layers of circular lenses with gradually increased radius from top to bottom, wherein the lenses at the uppermost layer are circular sheets, the lenses at the other layers are circular sheets with circular grooves hollowed in the center, and the dielectric constants of the lenses at each layer from top to bottom are sequentially reduced; The five microstrip patch antennas are arranged in one dimension, wherein the microstrip patch antennas at two sides are used as dummy elements, the three microstrip patch antennas in the middle are used as radiating units, the working mode of the radiating units is controlled, and the directional diagram reconstruction is realized; the metal cavity is formed by a square metal fence and a floor, the low-profile Maxwell fish eye lens is positioned in the metal cavity, and the microstrip patch antenna is nested on the floor of the metal cavity.
2. 2. A low profile maxwell fisheye lens based large pitch sparse phased array antenna according to claim 1 wherein K is a positive integer greater than 5.
3. 3. A low profile maxwell fish-eye lens based large pitch sparse phased array antenna as claimed in claim 1 or 2, wherein M, N is any positive integer.
4. 4. A low profile maxwell fish-eye lens based large pitch sparse phased array antenna of claim 3 wherein the outer side of the bottommost lens of the low profile maxwell fish-eye lens is cut out of 4 circular arc portions, and the 4 cut out faces are parallel to the 4 faces of the square metal fence, respectively.

Description

Large-spacing sparse phased array antenna based on low-profile Maxwell fisheye lens Technical Field The invention belongs to the technical field of microwave antennas, and particularly relates to a large-space grating lobe suppression sparse phased array antenna based on Maxwell fisheye lenses. Background With the iterative update of modern communication technology, phased array antenna technology is widely applied to various communication systems, such as various radars, base stations and other devices by virtue of the electric scanning characteristic of the phased array antenna technology. However, due to the high cost of the phased array system, the overall cost of the radar system is increased, wherein the T/R components occupy 60% to 80% of the cost of the entire phased array system, and therefore, the number of the T/R components is reduced while the radiation characteristics are kept unchanged, and the T/R components are one of hot spot directions of the current low-cost phased array research. However, by enlarging the space, the method of reducing the number of T/R components can cause the problems of grating lobes, array antenna gain loss and the like, so that the research on the large-space low-cost sparse phased array antenna technology with good radiation characteristics is particularly important. Patent document CN113851833a (application number CN 202111220999.7) discloses a grating lobe suppression wide-angle scanning phased array antenna based on a pattern reconfigurable subarray technology, the antenna is composed of a plurality of subarrays which are arranged periodically, the array element distance is 1λ in the y direction, the x direction is 0.5λ, zero point alignment is carried out through the subarray pattern and the array factor pattern, xoz face ±50° scanning and yoz face ±30° scanning are realized in a frequency band, and the grating lobe is suppressed to below-8.6 dB. Thereby eliminating grating lobes caused by the large pitch array. However, this method may result in gain loss of the array antenna, and the large-pitch scanning angle is limited, and the difficulty of antenna processing and stability during operation may be affected by the multi-layer structure and the complex feed network design of the subarrays. Patent document CN112803174a (application number CN 202110104425.7) discloses a large-pitch phased array and grating lobe suppression method based on a zero-point scanning antenna, the antenna also comprises a multi-layer structure, the unit pitch is 0.8λ, grating lobes caused by large-pitch arrangement are suppressed by adopting a zero-point alignment method, and scanning at ±55° is realized. However, the multilayer structure is complex, the processing difficulty is high, the working stability is limited, the array element spacing is only enlarged to 0.8λ, the number of reduced T/R components is limited, and the cost of the phased array antenna system cannot be obviously reduced. Patent document CN111985145A (application number CN 201910423768.2) discloses a large-space phased array antenna grating lobe suppression method, which optimizes the position information of antenna array elements by genetic algorithm through genetic optimization algorithm to suppress grating lobes below-8 dB. However, the method makes the design of the radio frequency circuit, the T/R component and the power division circuit at the rear end of the phased array antenna system very complex, improves the complexity of the design of the whole antenna system, and is not suitable for actual industrial production. Patent document CN114678688a (application No. CN202210418800. X) discloses a novel low-cost phased array feed network, which is composed of a plurality of single layers of C-BFN, and finally achieves the effect of 56% reduction of the phase shifter. However, the method has large energy loss, the scanning angle is limited by the array element spacing, and when the array element spacing is not less than 0.5λ, the scanning angle of the antenna is less than 30 °. Patent document CN114421178a (application number CN202210336470. X) discloses a luneberg lens phased array antenna, which adopts a luneberg lens to perform beam deflection, and switches different feeds, so that beam deflection at different angles can be realized. The method can improve gain and expand scanning angle, but has limited scanning precision, and the section of the luneberg lens is higher, and sometimes the antenna array needs to be designed into arc arrangement, and the antenna array is tightly attached to the edge of the lens to feed, thus having certain obstruction to practical industrial application. Two major problems currently encountered with large-pitch antenna arrays are 1. Grating lobe suppression, 2. Gain loss. Therefore, the study on the low-cost phased array antenna should pay attention to the following points of 1. Inhibiting grating lobes caused by large-space array, 2. Reducing gain loss and keeping radiation char