6 to 18 GhZ MMIC Phase Shifter: A New High Performance Switch MESFET

Multioctave Phase Shifters are key items in E.W. systems. On the market only few MMIC items are available, whose performances are not good enough for some special application. The way how to improve the performances doesn\´t involve the circuit, which is pretty classical: improving the switching FET will lead to more significant achievements. For the well known reasons, (1), we decided to use MESFET as switching elements. Therefore we designed together the Phase Shifter and its switching element, tayloring the two designs one on each other. The main goals to the design were: a). reduction of the "ON" resistances; b). reduction of "ON" capacitances. We obtained the result at the expences of the "OFF" state parameters, which exceeded the goal performances in the device we wanted to improve. We performed the simulations using EESOF and SONNET C.A.D., for the circuits, and HELENA for MESFET simulations.