Multi-bandpass filter based on multimode resonator

Abstract

The invention discloses a multi-bandpass filter based on a multimode resonator and mainly solves the problem of large size and poor performance of the multi-bandpass filter. The multi-bandpass filter based on the multimode resonator comprises a micro-strip dielectric substrate (1), a metal earth plate (2), a resonator (3) and an input-output feeder line (4). The resonator (3) is composed of two identical five-mode resonators which are staggered, each five-mode resonator is composed of a short-circuit branch (31), an open-circuit branch (32), a U-shaped microstrip line (33), a bulged loop (34) and L-shaped open-circuit branches (35 and 36). The symmetric center of the bulged loop (34) is superposed with that of the U-shaped microstrip line, and the top end of the bulged loop is connected with the bottom end of the U-shaped microstrip line. The L-shaped open-circuit branches are connected at the bottom end of the U-shaped microstrip line. The input-output feeder line (4) is composed of a pair of quasi fork-finger type coupled feeder lines. The size of the multi-bandpass filter can be reduced, design complexity is reduced, bandpass selectivity is improved, and the multi-bandpass filter can be used for a wireless communication system.

Description

technical field

[0001] The invention belongs to the technical field of electronic devices, and in particular relates to the design of a microstrip multi-passband filter, which can be used for a radio frequency front end of a wireless communication system. Background technique

[0002] Microwave filters are an indispensable and important part of communication systems, radar systems, and measurement systems. Therefore, microwave filters have always been the focus and hotspot of wireless communication system research. Modern wireless communication systems require radio frequency devices to work in multiple separate frequency bands to meet the needs of a multi-mode terminal to achieve different services, and transmit frequency signals of multiple discontinuous channels through one beam. This requires the use of multi-passband filters to suppress spurious noise signals. In the past, in order to realize multi-band communication, each frequency band required an independent filter,...

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