Multilayer Balanced-to-Unbalanced Power Divider with Wideband Transmission Characteristic and Common-Mode Suppression

This paper presents a wideband multilayer balanced-to-unbalanced (BTUB) power divider consisting of three metallic layers and two substrate layers with inherent common-mode suppression. With very simple structure, the working mechanism of the proposed power divider is investigated through even- and odd-mode equivalent circuit analysis, and the designed procedure is also summarized. For demonstration, an example of wideband BTUB power divider is implemented through standard printed circuit board process. The bandwidth of 63% of the fabricated BTUB power divider can be obtained with the best differential-mode transmission coefficient of -3.45 dB. The isolation bandwidth of approximately 63% can also be achieved. Good agreement between the simulated and measured results is observed, where the measured -15 dB common-mode suppression bandwidth is about 95%. Besides, the performance is stable after adding the shielding cavity.