A Cross-Coupling-Based Design of Filtering Power Divider

Filters and power dividers, as important devices in RF transceivers, are usually designed independently and then connected together by 50 ohm transmission lines. The resulting matching network and cascade lines not only increase the system size, but also generate losses and thus reduce efficiency. In this paper, a fourth-order open-loop filter based on cross-coupling is designed, introducing two transmission zeros to optimize the filter performance and reduce the filter size, and finally cascading a wilkinson power divider to achieve power distribution. Simulation results show that the filtering power divider operates in the frequency band 4.75~5GHz, with return loss greater than 10dB, insertion loss less than 4.5dB and output port isolation greater than 18dB.