Design of Unequal Dual Band Gysel Power Divider With Isolation Bandwidth Improvement

This letter presents a new design of an unequal dual band Gysel power divider (GPD) with isolation bandwidth (IW) improvement, which contains two grounded resistors for better power-handling capability (PHC), one resistor between output ports for enhancing the IW, an extension line at the input and a single stub line at the end for dual band operation, and ten branch line sections. Exact closed-form equations are derived for the proposed structure. For verification, the proposed structure is simulated, fabricated, and measured using microstrip lines. Simulation and measurement results show wide IW, while maintaining high PHC over the Wilkinson PD.