Computer aided design and evaluation of MIC hybrid coupled PIN diode phase shifters

A rigourous comprehensive analysis has been made for hybrid coupled PIN diode phase shifters for optimal performance. A detailed design procedure taking into account the effective diode and circuit parameters is given. Analytical expressions are derived for insertion loss, phase shift and power handling capability. A complete study is made to cover three important cases, namely, idealization of PIN diodes in normal or inverse modes, optimization of characteristic impedance for equalized loss in the two bias states and optimization of characteristic impedance for maximum power handling capability. It is shown that idealization of diodes becomes redundant when optimization of phase shifter is carried out for equalized loss. The performance of the phase shifters have been evaluated by numerically solving the analytical expressions for four different sets of practical diode parameters. Experimental verification of insertion loss and phase shift show good correlation with the derived expressions.