Tunable power divider based on coupled resonator with high-selectivity filtering response

This paper presents a novel tunable filtering power divider with high selectivity and good out-of-band rejection performance. The proposed design utilizes four coupled resonators to obtain the dual functions of power division and filtering. Varactors and resistors are added to enable frequency tuning and enhance the isolation performance, respectively. The circuit is theoretically characterized and implemented for demonstration. The operating frequency can be tuned from 0.83 to 1.13 GHz with good filtering and power division performance. The comparisons of the measured and simulated results are presented to verify the proposed method.