A study of square loop resonator filter at 2350 MHz for nanosatellite application

Tel-USAT payload communication block consists of S-Band transmitter, narrow band pass filter, and low dimension antenna in simplex mode. Filter selects the signal at certain frequencies to minimize the interference from adjacent frequencies. For nanosatellite application, filter has some requirements: small dimension, space proven material, and narrow bandwidth. One of methods that meets the requirements is a loop resonator. In designation of the loop resonator, there are some modifications such as chamfer in the corner of resonator, gap to avoid the loosely coupled and perturbation. The filter in the dimension of 40mm × 40mm × 1.67mm with FR4 dielectric material has obtained 44dB return loss or 1% reflected power back to input port, 6dB insertion loss, and phase shift 180 degree in linear characteristic.