An In-phase Balanced-to-Single-Ended Power Divider with Different Power Division

Configured by ±90° and 180° transmission line sections and one resistor, the proposed design is capable of achieving different power division ratios for differential-mode signal with the circuit parameters derived by using the constraint rules of the S-parameters. Two kinds of coupling structures are presented as the -90° transmission line section for size reduction and enhancement of maximum power division ratio up to 11. 6∶ 1. Two prototypes with power division ratios of 1∶ 1 and 7∶ 1 are measured with the minimum insertion losses varying from 0. 3 dB to 0. 4 dB and compared with the reported designs. The measured operating bandwidths for SddAA < -20 dB are 14. 3% and 11. 1%, respectively. Over the operating bandwidths, the isolation and common-mode suppression are all higher than 20 dB, and the phase difference between the two output ports are within ±5°. Therefore, the proposed designs with different power division ratios exhibit the merits of compact size, common-mode suppression, and easy integration with both balanced and single-ended circuits.