Design method for linear amplifier

摘要

A method of designing a linear rf amplifier comprising an output load impedance and an active device including the steps of (a) applying DC bias to the device, (b) applying two different frequency signals of an amplitude C, and (c) changing the value of the load impedance and recording the impedance value and associated C/I ratio for each impedance value (C/I being the ratio of amplitude C and amplitude I-the amplitude of an intermodulation product frequency). The last step (c) is repeated for a plurality of output levels. The above is repeated for a plurality of input power levels. The next step is selecting from the recorded information the impedance values corresponding to the maximum C/I ratio and recording the impedance values and corresponding C/I ratios, input power levels and output power levels. Then, choosing a desired C/I ratio from those recorded in the previous step and selecting the impedance value corresponding to the maximum output power level.