Design and characterization of variable attenuators and phase shifters with linearized bias control voltages

We first present the design, fabrication and test of a voltage controlled variable attenuator and a voltage controlled variable phase shifter. The designs use a reflection-type topology with PIN diodes for the attenuator and varactor diodes for the phase shifter. Two measurement-based diode models are developed to optimize the design and ensure first-pass success during fabrication. These models capture both DC and S-parameter behavior of the devices. Various impedance transformation topologies are investigated to maximize the dynamic ranges while minimizing phase-shift, for the attenuator, and insertion loss, for the phase shifter. The optimized designs are then fabricated and the linearization of the bias control voltage is investigated using both digital and analog approaches. The topologies of both configurations are presented and discussed and results of their implementations are presented.