Frequency Tunable Filtering Power Divider With Arbitrary Power Division Ratio and Transmission Zeros

This paper presents a novel design of filtering power divider (FPD) with tunable center frequency and an arbitrary power division ratio. The proposed FPD is designed using two dual-mode resonators and exhibits high frequency selective characteristics by generating transmission zeros on either side of passbands. The passband frequency can be continuously tuned by adjusting even and odd-mode resonant frequencies of dual-mode resonators. To validate the design, a microstrip line FPD with equal power divider ratio is designed and fabricated. The experimental results show that the passband frequency is tuned from 1.35 GHz to 1.90 GHz by adjusting single dc-bias voltage of varactor diode. The in-band transmission insertion loss is remained between 1.30 dB and 2.34 dB (excluding inherent loss of power divider) while maintaining frequency selective characteristics.