SCHOTTKY DIODES FOR ANALOG PHASE SHIFTERS IN GALLS MMICS

A simple Schottky diode structure, which is easily implemented in a fo undry gallium arsenide (GaAs) process, is described. This structure oc cupies very much less area than the usual technique of realising Schot tky diodes? using standard FET structures, Two variations of the diode have been characterized and modeled using a standard equivalent circu it. This has been used to design a simple analogue phase shifter based on a loaded-line configuration. The phase shifter was manufactured us ing a standard foundry process and has shown excellent results in term s of phase shift linearity with tuning voltage, combined with low inse rtion loss, over the range 2-8 GHz.