A Balanced-to-Balanced Power Divider With Wide Bandwidth

In this letter, a balanced-to-balanced power divider (PD) is proposed. By etching both slot and aperture on the common ground of the back-to-back microstrip Wilkinson PD, the proposed balanced-to-balanced PD can achieve wide and high common-mode (CM) suppression while keeping the PD function for differential-mode signals. Compared with previous technologies of CM suppression for back-to-back microstrip balanced circuits, the proposed one has the advantage of compact size. Furthermore, the proposed PD shows enhanced bandwidth for matching and isolation. A prototype is realized with the size of 0.35 λ_g × 0.4 λ_g. The measured results show relative frequency bandwidth for dB of 85%. The fractional bandwidths for |S_dd32|, |S_cc21| and |S_cc32| under -20 dB are 44%, 44% and 55%, respectively.