Design and Evaluation of Modified Reflective Predistortion Linearizer with Tunable Compensation

We reported the design and evaluation of a modified reflective pre-distortion linearizer with tunable compensation within the same power compensation interval for microwave power amplifier. The original work included adoption of a varactor-diode in the nonlinear generation circuit and removal of the troublesome bias voltage on Schottky diode, because it negatively affects the compensation interval. The pre-distortion compensation could be easily realized by changing the bias of the varactor-diode. The prototyped, modified reflective pre-distortion linearizer, designed to operate in 29~31 GHz range, was simulated and measured. The simulated test results show that it works pretty well. To be specific, in the same power range, as the bias voltage applied on the varactor-diode increased from 0 to 6 V, the gain expansion changed from 4. 5 to 7. 6 d B and the phase expansion varied from 3. 4° to 51.1°.