A kind of RF circuit of microwave analog predistorter

A kind of analog RF predistorter is introduced which comprises the analog attenuator,the analog phase-shifter and the 3 dB electrical bridge.The linearity of the amplifier is improved by locating the predistorter at the inputting port of the microwave amplifier and regulating the bias circuit of the predistorter.Two-tone measurements performed with the ADS software demonstrates that the third order intermodulation products can be suppressed by more than 20 dBc.