A 1–42 GHz GaN Distributed Amplifier With Adjustable Gain by Voltage-Controlled Switch

A 1–42 GHz gain-variable distributed amplifier is presented in the letter using a 0.13- $\mu \text{m}$ gallium nitride (GaN) process. The amplifier can achieve a gain tuning range of about 3 dB over the entire frequency band by voltage-controlled switching. The chip area of the amplifier is about $1.9\times1.1$ mm ² . The average output power of the amplifier is greater than 27.5 dBm over the entire bandwidth. A wider gain tuning range can be achieved by adding more voltage-controlled switches.