BAND-PASS FILTER BASED ON RING RESONATOR

摘要

The present invention provides a band-pass filter based on a ring resonator. The band-pass filter comprises: a dielectric slab; a ground metal layer provided on the lower surface of the dielectric slab; and an input end, an output end, an input microstrip line, an output microstrip line, a first coupling line, a second coupling line, a ring resonator, a first double-stub open load, a second double-stub open load, a first double-stub impedance matcher, and a second double-stub impedance matcher which are formed on the upper surface of the dielectric slab by means of etching. The band-pass filter is symmetrical about a central axis. According to the present invention, the band-pass filter is symmetrical about a central axis; a ring resonator is formed by the middlemost four microstrip lines, and a double-stub open load is separately loaded at the input end and the output end, to bring a good band-pass matching effect for the band-pass filter within a working band, apply a good inhibitory effect on out-of-band signals, achieve high selectivity on passband signals, introduce less noise, and avoid interference with a radio frequency front end.