ANALYSIS OF THE SUBHARMONIC LOAD PULL CHARACTERISTIC OF THE MESFET POWER AMPLIFIER PRECISELY WITH THE VOLTERRA SERIES METHOD
用VOLTERRA 级数精确分析 MESFET 功率放大器的副谐波负载牵引特性

In order to analyze the subharmonic load pull characteristic of the MESPET power amplifier driven by CDMA type wide band signal, a set of Volterra transfer funcion expressions arc deducted with the MESFET nonlinear model. With these expressions, the relation between the IM3 (third order intermodulation) and the subharmonic impedance is established, and the characteristic of the subharmonic load pull is analyzed. The expression of the optimal subharmonic load is also given with the analysis. It is proved in the paper that the reactance part of the subharmonic impedance is the main factor that leads to the difference of the two IM3. The result of the analysis agrees well with the simulation result got from ADS with harmonic balance method.