A Planar Balanced-to-Balanced Power Divider With Wideband Filtering Responses and Common-Mode Suppressions

In this paper, a balanced-to-balanced power divider with a wideband filtering function is proposed. The power divider is simply composed of coupled-line sections, λ/4 lines and isolation resistors, and explicit design methodology is given. From the simulated and measured results, the power divider shows 49% differential-mode filtering bandwidth with two additional transmission zeros introduced, and the common-mode transmission is suppressed below -12 dB over 141% frequency bandwidth. This power divider can be a candidate for constructing fully-balanced systems.