RF POWER AMPLIFIER WITH LOW INTERMODULATION DISTORTION AND REDUCED MEMORY EFFECT

摘要

A radio-frequency (RF) power amplifier includes an active device, having an input port, which is coupled to receive an RF input signal having a center frequency f0 and a single-sided bandwidth BW, and an output port, which is characterized by an output capacitance C1 and is coupled to output an amplified RF signal, responsive to the input signal, with a peak output power Pout. A distortion suppression circuit is coupled between the output port and a ground, and includes a transmission line having a characteristic impedance Z0 that is selected so as to substantially satisfy a condition that 1 $Z_0\le \frac{f_0}{\mathrm{pi}\mathrm{BW}}·\frac{1}{\sqrt{\frac{P_{\mathrm{out}}}{11.3}}+4\mathrm{pi}\mathrm{BW}·C_1}.$