A Hybrid Simulation Model for Characterization of Nonlinear Circuits Using Harmonic Radar

A realistic simulation model to obtain harmonic power curves of nonlinear circuits using harmonic radar is proposed in this study. Advanced Design System (ADS) and High Frequency Structural Simulator (HFSS) are used as simulation tools. HFSS is used for modelling free space radiation and ADS is used for circuit modelling. Three different circuits are modelled in ADS which are diode clamper, diode limiter and full wave rectifier. In HFSS part of the simulation, wideband Vivaldi antennas are modelled as radar transmit and receive antennas. To couple radiated power on electronic circuits, a single opportunity dipole antenna tuned to radar transmit frequency is used. Similarly to reradiate the harmonics generated by electronic circuits back to the radar, a log periodic dipole antenna is modelled as an opportunity transmit antenna. Sweeping electromagnetic power level from 0 to 40 dBm on the transmit antenna, nonlinear variation of reflected harmonic powers due to nonlinear components are observed.