Compact UWB bandpass filters with two superposable notched bands

Abstract

In this article, compact microstrip ultrawideband (UWB) bandpass filters with two superposable notched bands are discussed. By cascading n + 1 T‐shaped structures where n = 1 or 2 to a three coupled‐line section, UWB bandpass frequency response with one or two notched bands can be obtained. The analysis shows that these notched bands are superposable and can be relatively independently adjusted in wide frequency range. The simulated and measured results are presented for verification. The filters are characterized by easy tuning and compact size. © 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 57:2819–2824, 2015