Enhancing Load Range of Concurrent Dual-band Real to Real Matching Network Using Load Shifters

This paper presents enhancement of the load range of dual band real to real matching networks for a given frequency ratio through load shifters. The proposed structure is a simple L-section and has versatility to serve any impedance environment ranging from almost a short circuit to nearly an open circuit for any frequency ratio. In this paper, the cascaded stepped impedance structure proposed by Monzon is analyzed in details using Smith chart, and its limitations regarding the load range with increase in frequency ratio have been studied. The proposed load shifter has been successfully applied to Monzon's structure at larger frequency ratios for both small and large loads. The simulated and the measured results are in a good accordance. This structure can also be used with any other regular matching network capable of matching limited range of load.