A planar balanced power divider with tunable power-dividing ratio

This paper reports on, for the first time, the design and implementation of planar balanced tunable power dividers. The wide power-dividing tuning range is obtained by using two tuning capacitors and a single control voltage. The differential-mode operation, common-mode rejection, and cross-mode conversion suppression are realized for all tuning states. Closed-form equations for design parameters are derived. For verification, a power divider operating at 1 GHz with power-dividing tuning ratio of 0.01-3.61 is designed based on the given closed-form design equations. Finally, a microstrip tunable power divider with two varactor diodes MA46H202 is fabricated and measured. The measured results are in good agreement with the simulated ones.