Planar balanced-to-unbalanced power divider

A novel wideband balanced-to-unbalanced filtering power dividers based on coupled lines is proposed in this paper. The multi-functional power dividers can replace various cascaded single devices to decrease integration mismatching loss and circuit size. The wideband response can be easily realized by using the coupled lines structures. In addition, a resistor is introduced in the middle of two single-ended ports to realize isolation between output ports. To verify the proposed strategy, a wideband balanced-to-unbalanced filtering power divider operating at 2 GHz is designed and fabricated with 4-dB differential-mode bandwidth of 80.5%.