Design of compact wideband filtering power divider with extended isolation and rejection bandwidth

Abstract

A wideband filtering power divider (FPD) with good isolation and widen upper stopband is presented. A distributed stepped-impedance resonator (SIR) network composed of three short-circuited SIRs and one isolation resistor is introduced to obtain both port-to-port isolation and harmonic suppression. For demonstration, an FPD operating at 2.3 GHz with 3 dB fractional bandwidth of 31% is designed, fabricated and measured. In the operating band, the measured isolation is better than 17 dB, while out of band, the upper stopband is extended to 9.8 GHz (4.2f 0) with a rejection level of 20 dB.