A Simple Microstrip Bandstop Filter Using Cross-Coupling Stubs

Abstract EN

This paper presents an alterative implementation of a shunt open-circuited stub for multilayer microwave circuit.

With making use of the proposed implementation, a simple and compact bandstop filter with a district bandstop characteristics and a first spurious at the third harmonic is proposed.

The proposed filter exhibits about 12.5% fractional bandwidth of −10 dB signal rejection at the center frequency of 2.04 GHz and flat group delay at the pass bands.

Besides, by cascading a number of the proposed bandstop filters designed at the different frequencies, multiband bandstop filters can be easily realized.

A dual- (tri-) band design at the center frequencies of 2 GHz and 3 GHz (and 4 GHz) is designed, realized, and measured.

The proposed bandstop filter well suits the nowadays multilayer and compact radio frequency integrated circuit design.