Coplanar Waveguide Filters Based on Multibehavior Etched-Ground Stubs

In this paper, coplanar waveguide filters with etched-ground stubs that have multiple behaviors are proposed. The response of a unit cell is a band reject with one or more transmission zeros according to the number and the lengths of the stubs. A library of transmission line models is being built for the basic cells and then used for the design of more elaborated structures. The potential of these new topologies is highlighted by providing different filtering structures with interesting features: a second-order narrow bandpass filter, and two configurations for a lowpass filter with a wide stopband. All theoretical predictions have been verified by electromagnetic simulation and measurements.