A New Uniplanar Bandpass Filter using λg/2 Slotline and λg/4 Coplanar Waveguide Resonators

This paper describes the design and performance of a new BP filter using λg/2 slotline and λg/4 CPW short-end resonators. A compact circuit, with an optimized geometry of the slotline elements, to reduce radiation loss, has been fabricated and tested. The experimental results with a center frequency of 8 GHz and a bandwidth of about 50% are shown, and compared to the simulation of a simple transmission line electrical model; a very good agreement is obtained between them over a very large bandwidth, as well in the passband as in the stopband.