Phase-only multi-beam directional diagram synthesis method based on separation calibration iteration FFT (Fast Fourier Transform)

Abstract

The invention discloses a phase-only multi-beam directional diagram synthesis method based on separation calibration iteration FFT. The method comprises the following steps of generating an initial excitation phase, performing phase-only optimization on initial excitation and selecting an optimal excitation phase. The invention provides an iterative fast Fourier transform (FFT) technology for beam separation calibration, which is inspired by a Schirkunov unit circle, the technology decomposes a multi-beam directional diagram into a plurality of single-beam directional diagrams during each iteration, utilizes forward FFT to solve the excitation of the multiple single-beam directional diagrams, calibrates all the excitation and then adds the excitation, and a calibrated multi-beam directional diagram is obtained through reverse FFT, in addition, an amplitude directional diagram is continuously modified in iteration so as to reduce the side lobe level and lift a main lobe with a low peak value, meanwhile, multiple initial solutions are subjected to multiple times of phase-only optimization so as to achieve the lower side lobe level, and only the excitation phase of an array element is optimized in the method, and the complexity of the feed network can be effectively reduced.

Description

technical field [0001] The invention relates to the technical field of array antennas, in particular to a phase-only multi-beam pattern synthesis method based on separate calibration iterative FFT. Background technique [0002] There are multiple main lobes with different pointing angles in the multi-beam pattern, which can serve multiple targets at the same time in wireless communication. In recent years, multi-beam array antennas have been widely used in point-to-multipoint information transmission systems, point-to-multipoint In broadcasting systems and millimeter-wave communications, there have been many studies on the synthesis of multi-beam patterns. In order to obtain multi-beam patterns with lower sidelobes, most research methods choose to optimize the excitation amplitude and excitation phase at the same time to obtain better However, the optimization of the amplitude will introduce unequal power dividers, which will make the feed network more complicated. In practi...

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Problems solved by technology

[0002] There are multiple main lobes with different pointing angles in the multi-beam pattern, which can serve multiple targets at the same time in wireless communication. In recent years, multi-beam array antennas have been widely used in point-to-multipoint information transmission systems, point-to-multipoint In broadcasting systems and millimeter-wave communications, there have been many studies on the synthesis of multi-beam patterns. In order to obtain multi-beam patterns with lower sidelobes, most research methods choose to optimize the excitation amplitude and excitation phase at the same time to obtain better However, the optimization of the amplitude will introduce unequal power dividers, which will make the feed network more complicated. In practical applications, if uniform amplitude weighting can be used, the complexity of the feed network can be greatly simplified. To reduce the cost and weight of the array antenna system, it is of great significance to use phase-only optimization to synthesize multiple beams. In addition, it is worth noting that the phase-only synthesis method can also be used for multiple beams under the condition of given amplitude excitation. Beam synthesis, with high flexibility;

[0003] In recent years, some scholars have proposed a method of synthesizing multi-beam patterns by only optimizing the excitation phase of the array elements. However, these methods have been proposed so far either with insufficient efficiency, slow optimization synthesis speed, or inability to obtain lower sidelobe levels and accurate There are few methods that can efficiently synthesize low sidelobe beam pointing and accurate multi-beam pattern;

[0004] Chinese patent 202010988438.0 discloses a low-profile dual-beam patch antenna. This invention designs a stable patch antenna capable of radiating dual beams based on multi-mode resonance, which has a wide bandwidth, but because a single antenna has a low direction The shortcomings of inflexibility and inflexibility of beam scanning cannot meet the expected requirements in most long-distance communication applications;

[0005] Chinese patent 201910155480.1 discloses an array pattern synthesis method based on the non-uniform fast Fourier transform algorithm, which can quickly and effectively synthesize the pattern with lower sidelobes, and can also be applied to the synthesis of non-uniform arrays However, this method can only synthesize the low-sidelobe single-focus beam pattern, and cannot realize the synthesis of dual-beam and multi-beam;

[0006] Chinese patent 202010043954.6 discloses a multi-beam synthesis method based on a hybrid adaptive particle swarm optimization algorithm. This method uses a hybrid algorithm combining an improved adaptive particle swarm optimization algorithm and a genetic algorithm for multi-beam pattern synthesis, which expands the diversity of particles. property, which reduces the probability of particle swarms falling into local convergence prematurely, making it suitable for multi-beam synthesis of large-scale area arrays. The cost function, so the whole optimization and synthesis process is time-consuming, and this method optimizes the excitation amplitude and phase at the same time, and the non-uniform amplitude will introduce unequal power splitters, which will increase the complexity of the feed network;

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