Highly selective dual-band bandpass filter

Abstract

The present invention provides a dual-band bandpass filter with high selectivity, comprising two first microstrip lines, an input end, an output end, and a second microstrip line provided on the upper surface of a dielectric slab. Both ends of each first microstrip line are provided with an open load and a shorted load, respectively; the middle parts of the two first microstrip lines are connected by means of the second microstrip line; the input end is connected to one of the first microstrip lines, and the output end is connected to the other first microstrip line; both ends of the second microstrip line are respectively communicated with the input end and the output end, and are located on the same horizontal line; the horizontal line serves as a first central axis; a second central axis is perpendicular to the first central axis; the tail end of the shorted load is provided with a shorted metal post, which is connected to a ground metal layer provided on the lower surface of the dielectric slab. The dual-band bandpass filter with high selectivity of the present invention exerts a good suppression effect on out-of-band signals, has high selectivity, introduces less noise, and avoids interference to a radio frequency front end.

Description

technical field [0001] The invention relates to the technical field of radio frequency microwave communication, in particular to a high-selectivity dual-frequency bandpass filter. Background technique [0002] As a very important device in the RF front-end, the filter can filter out out-of-band noise and improve the sensitivity of the circuit system. A microstrip filter is a device used to separate microwave signals of different frequencies. Its main function is to suppress unwanted signals so that they cannot pass through the filter and only allow the required signals to pass. In a microwave circuit system, the performance of the filter has a great influence on the performance index of the circuit system. Due to the diversity of communication frequency bands in modern communication systems, the selectivity of the bandpass filter in the prior art is often insufficient to meet the requirements of the diversity of communication frequency bands, which affects the performance ...

AI Technical Summary

Problems solved by technology

[0003] The purpose of the present invention is to provide a high-selectivity dual-band band-pass filter, aiming at solving the technical problem that the selectivity of the existing band-pass filter is not high

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