Composite microstrip lowpass filter with ultrawide stopband and low insertion loss.

ABSTRACT A compact microstrip lowpass filter with a very wide passband is proposed in this article. The filter is based on generalized Chebyshev filter prototype of nine degree. The filter is designed to have a cut-off frequency at 18 GHz and a return loss of better than 20 dB. The design of the proposed filter is successfully realized in theory and verified by full-wave electromagnetic simulation and the experiment. An excellent agreement between the expected and measured results is obtained. The measured results show a low insertion loss of less than 1.5 dB over the entire ultrawide passband. The fabricated filter looks attractive for wideband RF/microwave systems due to its good performance and overall physical volume. © 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 57:871-874, 2015 [ABSTRACT FROM AUTHOR]