Study of the Linearity of a Transistorized Power Amplifier Operating in the 3.8 to 4.2. GHz Frequency Range

Abstract

The theoretical and experimental study of the reduction of the non-linearities of transistorized microwave amplifiers is explained here. The retained solution consists in comparing the input signal with the main amplifier's output signal. The intermodulation products created by the main amplifier are considered as an error signal which, after amplification, is re-injected at the appropriate amplitude level and phase value into the main network (this type of correction is called "feed forward"). The studied compensation networks allowed a 20 dB reduction of the intermodulation products' level. The adopted solutions are easily extrapolated and allow the compensation of amplifiers performing at higher frequencies and delivering higher powers.