Multi-Functional Filtering Power Divider with Tunable Center Frequency and Isolator Functionality

This paper introduces novel co-design approach of multi-functional power divider with tunable center frequency and non-reciprocal behavior (| S₂₁ | = | S₃₁| ≈/√2 and |S₁₂| = |S₁₃| ≈ 0) by employing spatio-temporal modulation technique. The nonreciprocal response is achieved by modulating its constituent resonators with progressive phase shift a sinusoidal signal. Through parametric numerical simulations, this paper establishes empirical relationships between modulation parameters and design specifications of the proposed nonreciprocal filtering power divider. To validate the proposed method, a non-reciprocal filtering power divider with tunable center was designed and fabricated. Measurement results demonstrate the effectiveness of the proposed approach, showing that passband center frequency is tuned from 1.67 GHz to 1.96 GHz while maintaining forward transmission insertion loss less than 4.8 dB and reverse isolation higher than 20 dB within passband.