A small-size semilumped three-port tunable power divider

In this paper, a small-size semi-lumped three-port power divider with both power and frequency tune is designed and measured. The proposed topology uses complex impedance transformers in each output branch. A 3D CPW prototype is realized with varactor diodes. It exhibits a wide tunable power, from -1.3 dB to -21 dB, and a wide working frequency tune, from 0.8 GHz to 1.4 GHz. Measurements and simulations are in good agreement.