Nonlinear Modeling, Analysis and Design of an Active Antenna in S Frequency Band

An active antenna for transmitter application in S frequency band is designed and analyzed using harmonic balance technique which is based on the nonlinear model of active devices. In this active antenna, the amplifier is integrated with the radiator which is a rectangular patch antenna. This patch antenna is analyzed employing full-wave momentum method. By applying nonlinear model of transistor in the amplifier and separating the linear and nonlinear parts, the harmonic balance equation is obtained. The splitting algorithm is applied to solve the harmonic balance equation and obtain the steady-state voltages at common port. The results of this method are compared with those of commercial simulators.