Design and Synthesis of a Chebyshev Response Waveguide Filter

In response to the rapid advancement in the millimeter-wave technology, high-performance filters are highly demanded to realize the design of a very sharp filter for narrowband applications. This paper presents the design, synthesis, and implementation of a WR-15 band (50-75 GHz) Chebyshev response waveguide filter. An insertion loss method is used for synthesis of the S-parameter responses of the desired filter. The filter is realized based on a sixth-order Chebyshev polynomial that provides the required out-of-band rejection level. The filter is demonstrated at 60 GHz with a fractional bandwidth of 2.67% by using the ANSYS High Frequency Structure Simulator (HFSS) software. The simulated S-parameter responses show a good agreement with those of the theoretical results. It depicts a low passband insertion loss of 0.51 dB, high lower and upper rejection levels of 93.56 dB and 82.31 dB at 57 GHz and 63 GHz, respectively, and a good return loss performance of 12.60 dB within the passband.