A liquid crystal phase shifter with continuously adjustable phase and its control method

Abstract

The invention relates to a liquid crystal phase shifter with continuously adjustable phase and a control method. It comprises an upper shell, a microwave dielectric plate and a lower shell in sequence from top to bottom. The lower shell is laid with liquid crystal at the center of one side facing the microwave dielectric plate. The liquid crystal is surrounded by a plastic frame, and the microwave dielectric plate is printed with a microstrip transmission line. The microstrip transmission line includes a liquid crystal material transmission section in the middle and a microwave material transmission section at both ends of the liquid crystal material transmission section. By optimizing the parameters of the interdigitated capacitors on both sides, the control method can form the effect of a bandpass filter, cut off the signal outside the required frequency band, and at the same time block the DC bias signal to the microstrip transmission line section, avoiding the interference caused by the DC signal. The bias voltage of the liquid crystal is controlled through the DC bias line, thereby controlling the change of the dielectric constant of the liquid crystal material, thereby changing the electrical length of the transmission line, and finally changing the phase shift of the signal. The invention realizes phase shift within 180° range, wider working frequency band and lower insertion loss.

Description

technical field [0001] The invention relates to a continuously adjustable liquid crystal phase shifter and a control method, belonging to the technical field of phase shifters. Background technique [0002] As a common microwave device, phase shifter is widely used in phased array radar, instrumentation, mobile communication and other fields. The essence of the phase shifter is to control the electrical length of the signal transmission path, thereby causing the transmission delay of the signal, and then achieving a phase delay that meets the requirements. [0003] Traditional phase shifters can only achieve fixed phase adjustment, while phased array antennas that realize intelligent beam steering often require phase shifters to have continuously adjustable phase offsets. There are usually two types of phase shifters with continuously adjustable phases: Implementation methods: mechanical phase modulation and electronic phase modulation. The former has high phase shift accu...

AI Technical Summary

Problems solved by technology

At present, researchers focus on expanding the phase shifting range and improving the response speed in the research of liquid crystal phase shifters. However, these technical difficulties are more limited by the properties of liquid crystal materials.

Based on the current technical status and production process of liquid crystal materials, liquid crystal phase shifters still have the shortcomings and technical difficulties of narrow operating bandwidth and high insertion loss.

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