A Balanced-to-Balanced Network With Unequal Power Division and Wideband Common Mode Suppression

A novel wideband balanced-to-balanced network with unequal power division is proposed in this letter. Two open stubs and half-wavelength transmission lines are used to realize wideband common mode suppression, two ideal double-sided parallel-strip line (DSPSL) 180° phase inverters with isolation resistors are used to realize high isolation for the power dividing output ports. A planar wideband balanced network with bandwidth of 38.6% (power division ratio: 1 : 2
²
) for the differential mode and over 113.6% common mode suppression (1.06-3.56 GHz, |S
_cc21,31
| <; -10 dB) is designed and fabricated.