suspended stripline low-pass filter design for wide stopband attenuation applications

This paper involves the design of asymmetrical generalized chebyshev low-pass lter realized with a suspended substrate strip line. the study presents the synthesis and design of an asymmetrical prototype with degree of 11, cut-o frequency of 2.5 ghz, better than 26 db as passband return loss and a broad stopband rejection of 55 db. the filter produces 11 transmission zeros (attenuation poles), one at infinity and 5 pairs located at finite frequencies offering better wide stopband attenuation performance as well as sharp selectivity. the filter is built based on suspended stripline structure (sss) using aluminium as a cavity and with 2mm as a ground spacing. the filter measurements show a reasonable agreement has been achieved with the simulated response.