Coplanar waveguide-based lowpass filters with non-uniform signal trace and ground planes

Abstract

In this paper, we propose a new and systematic methodology for the design of a coplanar waveguide (CPW) low pass filter (LPF). The widths of the signal trace and adjacent ground planes are continuously varied based on an optimization process to obtain predefined electrical characteristics taking into account physical constraints. A non-uniform CPW LPF with a 3.5 GHz cutoff frequency is designed, analytically verified, and simulated. Simulation results show input port matching, S11, better than −10 dB and transmission parameter, S21, in the order of −0.2 dB in the passband.