A 35-nm-gate-length InP, high-electron-mobility transistor (HEMT) with a high-indium-content channel as the key component was developed to produce an MMIC (monolithic microwave integrated circuit) power amplifier. With a shorter gate length than previous transistor generations, it allows for electrons to travel shorter distances. This results in higher frequency functionality. In addition, the fabrication process provides for a comprehensive passive component library of resistors, capacitors, airbridge wiring, and through-wafer vias that allow for transistor RF matching and power combining on-chip, making the measured 10-mW 338-GHz chip possible.
The amplifier module can be used in series with current ≈340 GHz RF sources to boost RF output power. The extremely high-frequency power amplifier module can be used for very-high-frequency wide-bandwidth communication, and higher resolution radars for civilian applications.
This work was done by Lorene A. Samoska, Todd C. Gaier, Mary M. Soria, and King Man Fung of Caltech and Vesna Radisic, William Deal, Kevin Leong, Xiao Bing Mei, Wayne Yoshida, Po-Hsin Liu, Jansen Uyeda, and Richard Lai of Northrop Grumman Corp. for NASA’s Jet Propulsion Laboratory.