A Hairpin Bandpass Filter

Abstract

The invention discloses a hairpin type bandpass filter, which comprises an upper metal layer, a dielectric substrate and a lower metal layer stacked in sequence, the upper metal layer is connected with the lower metal layer to form a resonant cavity, and the upper metal layer includes sequentially spaced The first resonator, the second resonator, the third resonator, the fourth resonator and the fifth resonator of the hairpin half-wavelength resonator, the openings of the first resonator, the third resonator and the fifth resonator are set upwards, The openings of the second resonator and the fourth resonator are set downward, the input resonant strip of the first resonator is connected with an input microstrip line, the output resonant strip of the fifth resonator is connected with an output microstrip line, and the input resonant strip and The output resonant strips are respectively extended by 1 / 4 wavelength along the closing directions of the first resonator and the fifth resonator by using a microstrip line. The filter can suppress the spurious passband at a higher frequency outside the passband, realize wide stopband characteristics, have good frequency selection characteristics, and have low insertion loss.

Description

technical field [0001] The present invention relates to a filter, and more particularly, to a hairpin band-pass filter. Background technique [0002] The radio frequency microwave bandpass filter is one of the important modules in the modern wireless communication system. With the rapid development of radio frequency integrated circuits and the increasingly dense spectrum resources, the system puts forward higher requirements on the performance and size of the filter. Spectrum resources The tension requires that the filter has better frequency selection characteristics, that is, good out-of-band rejection and low insertion loss, otherwise the signals of adjacent channels will cause interference. The microstrip hairpin structure filter has become the mainstream due to its compact structure, high out-of-band rejection, low cost, easy processing and integration. However, for microstrip hairpin bandpass filters, spurious passbands will appear at integer multiples of the design ...

AI Technical Summary

Problems solved by technology

However, for microstrip hairpin bandpass filters, spurious passbands will appear at integer multiples of the design frequency, affecting the overall performance of the filter

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