COMPACT SHARP CUTOFF WIDE STOPBAND MICROSTRIP LOW-PASS FILTER USING COMPLEMENTARY SPLIT RING RESONATOR

摘要

A novel compact microstrip low-pass filter (LPF) is proposed using open circuit stubs and square patches along with complementary split ring resonator (CSRR). It exhibits wide stopband and sharp rejection. A demonstration LPF, having 3-dB cutoff frequency of 1.45 GHz, was fabricated and measured. Measured passband to stopband attenuation slope is more than 355 dB/GHz. Measured rejection greater than 20 dB extends over more than 13.75 times of the 3-dB cutoff frequency. Electrical length of the filter is less than 12% of the guided wavelength at 3-dB cutoff frequency. Experimental and simulated results agree well.