A filtering power divider with high selectivity based on surface acoustic wave resonator

Abstract

In this paper, a novel filtering power divider (FPD) based on surface acoustic wave (SAW) resonators is proposed. The proposed FPD integrates the functions of a SAW resonator filtering structure and a power divider, providing highly selective filtering response at two output ports. Microstrip transmission lines, inductors, and SAW resonators are integrated to form the filtering structure that functionally substitutes the quarter-wavelength microstrip line in the traditional Wilkinson power divider. Owing to the symmetry of the circuit topology structure, odd- and even-mode methods are used for analysis. To validate the proposed technique, a high-selectivity FPD based on SAW resonators is designed and fabricated. Measurement results demonstrate an operating bandwidth (return loss > 15 dB) of 989.6–1006.5 MHz with a minimal insertion loss of 1.4 dB. Across the entire passband, the output port isolation exceeds 21 dB, and the shape factor (BW_3dB/BW_10dB) is 0.81. The FPD owns advantages of high frequency selectivity and good isolation.