Slotline-Based Balun with Wide Bandwidth and High Isolation

A slotline-based balun with wide bandwidth and high isolation is proposed in this paper. The proposed balun integrates Wilkinson power divider, which is devoted to improving the isolation between the differential output ports. By utilizing asymmetrical slotline and symmetrical output microstrip, the implemented balun achieves excellent balance performance and wideband response. The simulation results demonstrate a wideband property with a return loss better than 10 dB from 4.4 GHz to 20.4 GHz, an improved minimum isolation of 10 dB as well as competitive balance performances including 0.5 dB amplitude imbalance and 3. 7 phase imbalance.