A mHEMT Power-Reconfigurable Distributed Amplifier Using a Gain Cell Switching Technique

A power-reconfigurable distributed amplifier (DA) is implemented using a 130 nm metamorphic high-electron mobility transistor (mHEMT) process. Using a mHEMT process with excellent high-frequency characteristics, output power and efficiency at high frequencies are improved compared with the existing power-reconfigurable distributed amplifiers. In this article, a gain cell switching technique is proposed as the power reconfiguration method for the distributed amplifier. The gain cell switching technique expands the gain bandwidth and power reconfigurability more than the conventional bias control. The proposed power-reconfigurable DA obtains a measured linear gain of 10.0–13.6 dB from 0.5 to 62.5 GHz and a measured output power of 20.2–21.5 dBm from 10 to 40 GHz. A measured power added efficiency (PAE) is 11.6–20.0% from 10 to 40 GHz. Under a low power mode (LPM), it obtains a measured linear gain of 4.4–7.1 dB from 0.5 to 65 GHz and a measured output power of 14.7–15.9 dBm from 10 to 40 GHz. At 10 GHz, a drain efficiency (DE) is 11.4% at 5.6 dB power back-off. This is 6.5% higher than the conventional DA or more than twice as high.