Quasi-Lumped Element Implementation of a Wide-Band Dual-Band Filter Based on Reactance Transformations

Abstract

The synthesis and design of a quasi-lumped element dual-band filter is presented for a radiometry application. Band 1 is from 0.45 to 0.86 GHz and band 2 from 1.24 to 1.75 GHz. The filter circuit model has no theoretical bandwidth limitation and is implemented on multilayer substrate. Controlled suppression between the two bands is demonstrated. Agreement between simulation and measurement confirms the feasibility of the design method. The effect of dominant parasitic elements in the quasi-lumped element implementations is detailed.