A Tunable Resonant Cavity Based on Tunable Capacitance

Abstract

The invention belongs to the field of communication, and provides an adjustable resonant cavity based on an adjustable capacitance, including a metal cavity with a similar coaxial structure, an insulating dielectric ring, a ferroelectric film, a capacitor electrode and a tuning electrode; the metal cavity with a similar coaxial structure There is an open ring on the top, and the insulating medium ring is filled into the open ring; the ferroelectric film is set at the center above the metal cavity, and the radius is greater than or equal to the inner radius of the insulating medium ring; the tuning electrode is set at the center above the ferroelectric film; the capacitor electrode is The ring electrode is arranged around the tuning electrode, and the outer edge of the capacitor electrode is connected with the metal cavity, and the inner edge of the capacitor electrode forms a parallel capacitor plate structure with the ferroelectric thin film and the metal cavity. The present invention adopts the adjustable capacitor made of ferroelectric thin film; firstly, the problem of mechanical fatigue is avoided, and the service life of the resonant cavity is prolonged; secondly, the tuning voltage only needs to reach 30 volts, which makes tuning easier; finally, due to the ferroelectric material The extremely fast response speed also increases the tuning speed of the resonant cavity.

Description

technical field [0001] The invention belongs to the communication field and relates to designing an adjustable filter, in particular to an adjustable resonant cavity based on an adjustable capacitance. Background technique [0002] The electromagnetic environment in which electronic communication equipment in modern warfare lives has become more and more complicated, and the threat of interference is becoming more and more serious. The struggle between interference and anti-interference has become the focus of research in modern electronic warfare. Due to the continuous and rapid development of communication technology and the rapid progress of electronic countermeasure technology, the spectrum background of radio communication is becoming more and more complex. It is different from the previous electronic systems: high integration, high intelligence, and the combination of digital and analog signals have become new features of modern electronic systems. The research on the...

AI Technical Summary

Problems solved by technology

Based on these requirements, the commonly used solution is to use filters with different center frequencies to form a filter bank, but the obvious disadvantage of this solution is that it is expensive and bulky due to the use of multiple filters.

The single tunable filter solution is the most mature tunable filter based on YIG (yttrium iron garnet) technology, but this technology still has disadvantages such as large size, high power consumption, and difficulty in integration.

In addition, tunable filters based on technologies such as varactor diodes, ferroelectric thin films, and planar MEMS (micro-electromechanical systems) have appeared successively, but these filters either cannot meet the wide adjustable range, or cannot achieve high quality factor problem

In recent years, a tunable filter based on an evanescent mode cavity has attracted much attention due to its good quality factor and wide adjustable range; The unique mechanical adjustment method makes it have problems such as low service life, high applied voltage, and center frequency drift.

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