High-Efficiency, V-Band Solid-State Power Amplifier Using GaN

QuinStar Technology proposes to develop an efficient, solid-state power amplifier (SSPA), operating at V-band frequencies, for remote sensor applications. Specifically, we propose to develop an 8-W power amplifier with an associated PAE of >40% operating over the 65 to 70 GHz band. This will be accomplished by employing two major innovations. First, we plan to utilize wide bandgap Gallium Nitride (GaN) on Silicon Carbide (SiC) device technology. Operating at a higher voltage (typically 28 V versus 4 V for GaAs), GaN permits power densities which are 5-10 times higher than GaAs. In addition to power density, high-voltage operation results in lower matching and cell combining losses, making these MMICs more efficient. Secondly, we are proposing to utilize a switching mode (Class F) to enhance the device efficiency. While this method has demonstrated PAE levels of >80% at 2 GHz, it has not yet been demonstrated at V-band frequencies. Computer simulations, contained in this proposal, indicate that by using this method, MMIC PAE levels of 50% are possible over the 65-70 GHz band. Finally, we will utilize our high-efficiency, H-tee combiner technology to combine 4 of these chips to achieve 8 W output power across the 65 to 70 GHz band.