Wideband Balanced Network with High Isolation Using Double-Sided Parallel-Strip Line

A new wideband balanced power dividing/combining network with high isolation is proposed in this paper. The differential/common mode equivalent circuits of the balanced network can be easily reduced based on the matrix transformation. Two double-sided parallel-strip line (DSPSL) 180 ^° phase inverters loaded with four isolation resistors are used to realize high isolation for the power division output ports. A planar wideband balanced network with bandwidth 52.7% of (1.68-2.84 GHz, |Sdd21, Sdd31| > - 4 dB) for the differential mode and high isolation for the differential/common mode is designed and fabricated. The measured results show good agreement with the theoretical expectations.