Spurious Free Wide Stopband Waveguide Filter for Q-band Payload

This paper presents a high-performance, low-loss Q-band waveguide filter with a wide spurious free stopband. A 6-pole Chebyshev filter is designed with a stepped impedance waveguide resonator at 38GHz, which provides more than 50 dB rejection at 1.5 times center frequency. The filter far stopband performance is superior compared to the equivalent waveguide resonator filter with a minimal increase of insertion loss. The filter performance is stable over the temperature range from −20 deg. C to 80 deg. C with a frequency drift of 16.26 ppm.