One-dimensional holographic antenna for liquid crystal electronically controlled scanning gap waveguide based on amplitude weighting

Abstract

The invention provides a one-dimensional holographic antenna for a liquid crystal electronically controlled scanning gap waveguide based on amplitude weighting, which is characterized in that the upper layer of the gap waveguide is provided with a traveling wave groove for cutting off surface current so as to radiate energy to an external space, a suspended cubic block forms a high-impedance surface to guide electromagnetic waves, the surface impedance is very high in a certain frequency band, TM mode surface wave transmission and TE mode surface wave transmission are not supported, and when the excitation frequency is less than the resonant frequency, the surface impedance is inductive impedance, and TM surface waves are supported; when the excitation frequency is greater than the resonant frequency, the surface impedance is capacitive reactance, and TE surface waves are supported; when the excitation frequency is close to the resonant frequency, the surface impedance is very high, and the two modes cannot exist; multiple crystal blocks are respectively applied with external voltage for control, the antenna structure is subjected to multi-port feeding, the independent control of each feeding port on wave beams is realized by changing the liquid crystal anisotropic dielectric constant of each unit, and the high-performance requirements of applications and antenna wave beam scanning in a high-frequency-band electronic communication system are met.

Description

technical field [0001] The invention relates to the field of communication technology, in particular to a liquid crystal electronically controlled scanning gap waveguide one-dimensional holographic antenna based on amplitude weighting. Background technique [0002] In modern electronic communication systems, there are more and more requirements for antennas with low sidelobe, high efficiency, broadband, multi-polarization, and beam scanning capability. In view of the fact that the current beamforming is realized by controlling the amplitude and phase of the excitation current of the antenna element or the position of the array element, the traditional beam antenna based on the power division phase shifting network has a complex control method and a power division phase shifting network circuit structure, with large loss and high cost. High, narrow bandwidth, small scanning angle and other technical problems, and the traditional electronically controlled liquid crystal tuning...

AI Technical Summary

Problems solved by technology

In view of the fact that the current beamforming is realized by controlling the amplitude and phase of the excitation current of the antenna element or the position of the array element, the traditional beam antenna based on the power division phase shifting network has a complex control method and a power division phase shifting network circuit structure, with large loss and high cost. High, narrow bandwidth, small scanning angle and other technical problems, and the traditional electronically controlled liquid crystal tuning technology is to apply a high voltage to the complete whole liquid crystal, the control and change of each part of the liquid crystal distributed in the antenna by the applied voltage are the same Yes, very limited control over the antenna beam

When the operating frequency of the antenna rises to the millimeter wave frequency band, the traditional microstrip line has more stray radiation due to the semi-closed structure of the antenna, and the surface wave effect of the antenna is serious, resulting in low radiation efficiency of the antenna; the narrow side of the cross-section of the rectangular waveguide transmission line is too small , when used in the design of broadband waveguide slot arrays, the upper and lower metal layers need good electrical contact, resulting in higher processing accuracy and higher antenna costs; When designing the feed network, the efficiency of the antenna will be greatly reduced, so a new waveguide structure is urgently needed

The substrate-integrated waveguide also has the problem of dielectric mode loss. The bandwidth of the waveguide slot antenna is very low. When the operating frequency is high, the precision of the antenna is high, and the processing cost increases.

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