A Large-Signal Equivalent Circuit Model for Hyperabrupt P-N Junction Varactor Diodes

A large-signal equivalent circuit model is presented for a hyperabrupt p-n junction varactor diode (HJVD), suitable for nonlinear CAD and computer simulation. A new function is proposed to describe the nonlinear dependence of the junction capacitance on the applied voltage. Experimental measurements on several commercial devices are presented, showing excellent agreement with the model proposed, over a very wide range of applied voltages. A physical investigation of the doping profile of hyperabrupt p-n junctions is made and a method to determine the doping profile parameters for an assumed type of dopant distribution is presented. Finally, validation of the model is demonstrated in two particular applications.