A POLYIMIDE ALUMINA-CERAMIC MULTILAYER MIC ANALOG PHASE-SHIFTER WITH A LARGE PHASE-SHIFT/

This paper demonstrates a polyimide/alumina-ceramic multilayer MIC ana log phase shifter with a large phase shift. First, a novel active indu ctor, similar to the previously reported active inductor but with a sh unt variable resistor inserted in the feedback loop, is proposed for m iniaturizing the circuit. The chip size of the fabricated GaAs MESFET active inductor is less than 0.52 mm(2). Next, a low-loss analog phase shifter with a large phase shift is presented. This is constructed in an MIC structure with the active inductors, the varactor diodes and t he low-loss polyimide/alumina-ceramic multilayer broad-side coupler. F urthermore, since the amount of the phase shift is the sum of the two individual tuning ranges attributed to the active inductors and varact or diodes, a large phase shift is obtained compared to the case where only the varactor diodes are tunable. Thus, a phase shift of more than 270 degrees within 2-dB insertion loss from 2.1 to 2.4 GHz is obtaine d with the fabricated single-stage reflection-type analog phase shifte r. The total power consumption is less than 80 mW.