A New Concept of Partial Electric/Magnetic Walls for Application in Design of Balanced Bandpass Filters

Abstract

In this paper, a concept of partial electric/magnetic walls is proposed and applied to design a class of balanced bandpass filters on (modified) doublet topology with differential-mode (DM) transmission zeros (TZs). It is first demonstrated that the partial electric/magnetic walls are equivalently attained along certain parts of these balanced filters. Using this concept, a dual-mode ring balanced bandpass filter on modified doublet topology with two DM TZs is designed, fabricated, and measured. Furthermore, another balanced bandpass filter on doublet topology with three DM TZs and wide upper stopband is designed and implemented, so as to exhibit the attractive application of the proposed concept. Good agreements between the expected response, simulated results, and measure results are observed.