A millimeter wave large-signal model of GaAs planar Schottky varactor diodes based on a physical analysis is presented.The model consists of nonlinear resistances and capacitances of the junction region and external parasitic parameters.By analyzing the characteristics of the diode under reverse and forward bias,an extraction procedure of all of the parameters is addressed.To validate the newly proposed model,the PSVDs were fabricated based on a planar process and were measured using an automatic network analyzer.Measurement shows that the model exactly represents the behavior of GaAs PSVDs under a wide bias condition from -10 to 0.6 V and for frequencies up to 40 GHz. A millimeter wave large-signal model of GaAs planar Schottky varactor diodes based on a physical analysis is presented. The model consists of nonlinear resistances and capacitances of the junction region and external parasitic parameters.By analyzing the characteristics of the diode under reverse and forward bias , an extraction procedure of all of the parameters is addressed. To validate the newly proposed model, the PSVDs were fabricated based on a planar process and were measured using an automatic network analyzer. Measurement means that the model exactly represents the behavior of GaAs PSVDs under a wide bias condition from -10 to 0.6 V and for frequencies up to 40 GHz.