An Adjustable Linearization for RF Power Amplifier

This paper presented an adjustable analog predistortion linearization method for RF power amplifier. The linearization includes an attenuator, a phase shifter and an anti-parallel Schottky diode pair with DC bias, through adjusting these components, we can adjust predistortion characteristic of the linearization to be complementary to distortion characteristic of RF power amplifier. By cascading this linearization with power amplifier, we can improve linearity of amplifier. Firstly, we simulated the proposed predistortion linearization with software ADS, then the linearization was manufactured and tested together with RF power amplifier PTF080551. Experimental results show that we can adjust predistortion characteristic of the linearization to be closely complementary to distrotion characteristic of power amplifier PTF080551 as desired. After cascading the linearization with power amplifier PTF080551, more than 10dB improvement in IMD3 of the amplifier can be achieved. Furthermore, the linerarizaion is flexible and can be adjusted to linearize different amplifiers.