An X-Band Phase Noise Canceling Feedforward Amplifier in InP 250nm HBT Process

This paper introduces a feedforward amplifier with a noise cancellation scheme for optical frequency division applications implemented in the InP 250 nm Heterojunction Bipolar Transistors (HBT) process. A novel schematic for the amplifier is proposed to facilitate the integration of the feedforward noise canceling scheme, by reducing physical size and enhancing overall gain. The measurement of the fabricated amplifier demonstrates more than 16 dBm output power, lower than -155 dBc/Hz additive phase noise at 10 kHz offset from 9.5 GHz carrier while the amplifier is biased in class A operation mode. The measurement results illustrate the efficacy of the proposed schematic for noise canceling and suggest its potential in low-noise microwave signal generation.