Millimeter wave adjustable filter

Abstract

The invention discloses a millimeter wave adjustable filter. A millimeter wave filter structure can comprehensively consider low loss, rapid debugging, high Q values and miniaturization of the filter,sensitivity and the dynamic range of a system can be remarkably improved, and millimeter wave transceiving system performance is greatly improved. The millimeter wave filter structure comprises an upper substrate, a lower substrate and a metal carrier, a millimeter wave filter inverted micro-strip circuit is arranged on the upper substrate, a liquid crystal cavity is formed in the center of the lower substrate and filled with liquid crystal, feed lines electrically connected with the liquid crystal are arranged on two sides of the liquid crystal cavity, the upper substrate, the lower substrate and the metal carrier are sequentially arranged from top to bottom, a micro-strip metal wire in the millimeter wave filter inverted micro-strip circuit and the liquid crystal are closely combined, and a liquid crystal injection hole communicated with the liquid crystal cavity is formed in the upper substrate. The millimeter wave filter structure has good frequency reconfigurable characteristics.

Description

technical field [0001] The invention relates to the field of millimeter wave filtering, in particular to a millimeter wave tunable filter. Background technique [0002] It is well known that there are four main reconfigurable technologies for traditional millimeter-wave tunable filters: varactor diode regulation, MEMS switch regulation, ferroelectric regulation, and BST (barium strontium titanate: barium strontium titanate) thin film tuning technology. The tunable millimeter-wave tunable filter realized by varactor diode technology has the advantages of fast tuning speed, easy design and processing, and low cost, but this technology requires more varactor diodes and controllable power supplies, which is limited by the inductance of the diode package leads. Influence, there are many parasitic parameters, which lead to unsatisfactory passband characteristics; BST thin film tuning technology has simple manufacturing process, high dielectric tuning, low loss characteristics and ...

AI Technical Summary

Problems solved by technology

The tunable millimeter-wave tunable filter realized by varactor diode technology has the advantages of fast tuning speed, easy design and processing, and low cost, but this technology requires more varactor diodes and controllable power supplies, which is limited by the inductance of the diode package leads. Influence, there are many parasitic parameters, which lead to unsatisfactory passband characteristics; BST thin film tuning technology has simple manufacturing process, high dielectric tuning, low loss characteristics and fast switching speed, but the Q value is low and the varactor is relatively low. Small, poor linearity; MEMS switch control technology can only switch between on and off states, replace MEMS switches with MEMS variable capacitors to achieve continuous control, the tuning rate is small, but the technology is costly and difficult to process

Due to the restriction of hysteresis effect, the tuning method based on ferroelectric materials is difficult to improve the tuning speed, and has the disadvantages of large volume and high power consumption.

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