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

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.