Design of S-Band Source-Controlled MMIC Voltage Variable Attenuator

The design and simulation of S-Band (2-4 GHz) Voltage Variable Attenuator (VVA) using pseudomorphic High Electron Mobility Transistor (pHEMT) in AWR design environment 13 is presented in this paper. This attenuator can be used in Automatic Gain Control circuits and in calibration purposes. At frequency of 2 GHz, minimum attenuation (at control voltage of 3.95 V) is 2.71195 whereas maximum attenuation (at control voltage of −4 V) is 23.248. S11 and S22 are better than −7 dB. At all control voltage values except at minimum attenuation, the noise figure is less than and equal to the attenuation value. The operating principle of the circuit is also explained in the paper.