A T‐junction power divider with tunable operating frequency and dividing ratio

This letter presents a T‐junction power divider (PD) with both tunable operating frequency and dividing ratio, simultaneously. The proposed design consists of two adjustable 90° phase shifters and a pair of shunt stubs loaded with two varactor diodes. The operating frequency can be tuned by controlling the varactor diodes loaded onto the 90° phase shifters. In addition, the tunable shunt stubs comprised of a short circuited and an open circuited stubs loaded with varactor diodes are employed to realize impedance matching and different dividing ratios at accurate operating frequencies. For verification, a prototype of the proposed PD with dimensions of 25.9 mm × 50 mm is designed, fabricated, and measured. The measured results show that the operating frequency can be tuned from 1 to 1.55 GHz, while the power dividing ratio can be tuned from 2:1 to 20:1. Good agreement between the simulation and measurement results is observed.