Generalized Chebyshev Highpass Filter based on Suspended Stripline Structure (SSS) for Wideband Applications

This paper presents the method to transform generalized Chebyshev lowpass filter prototype to highpass filter based on Suspended Stripline Structure (SSS) technology. The study involves circuit analysis to determine generalized Chebyshev responses with a transmission zero at finite frequency. The transformation of the highpass filter from the lowpass filter prototype produces a cutoff frequency of 3.1 GHz with a return loss better than -20 dB. The design is simulated and measured on a Roger Duroid RO4350 with a dielectric constant, ɛ r of 3.48 and a thickness of 0.508 mm. The experimental results are in good agreement with the simulated results. This class of generalized Chebyshev highpass filter with finite transmission zero would be useful in any RF/ microwave communication systems particularly in wideband applications where the reduction of overall physical volume and weight as well as cost very important, while maintaining its excellent performance.