Hairpin type band-pass filter

Abstract

The invention discloses a hairpin type band-pass filter, which comprises an upper metal layer, a dielectric substrate and a lower metal layer which are sequentially stacked, and is characterized in that the upper metal layer and the lower metal layer are connected to form a resonant cavity, the upper metal layer comprises a hairpin type half-wavelength resonator, a first resonator, a second resonator, a third resonator, a fourth resonator and a fifth resonator, the fourth resonator and the fifth resonator are sequentially arranged at intervals, openings of the first resonator, the third resonator and the fifth resonator are arranged upwards, openings of the second resonator and the fourth resonator are arranged downwards, an input microstrip line is connected to an input resonance strip ofthe first resonator, an output microstrip line is connected to an output resonance strip of the fifth resonator, and the input resonance strip and the output resonance strip extend by 1/4 wavelengththrough the microstrip lines in the closed direction of the first resonator and the closed direction of the fifth resonator respectively. The filter can inhibit parasitic passband at a higher frequency outside a passband, realizes wide stop-band characteristic, has good frequency selection characteristic, and is low in 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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