A balanced sub-millimeter wave power amplifier

Abstract

In this paper, a new balanced sub-millimeter wave power amplifiers is presented. The amplifier uses CPW-grounded MIM capacitors to form low-loss, lumped element matching networks and uses a branchline coupler to achieve requisite quadrature phase shifts. The balanced amplifier achieves 12-dB small signal gain and 6.1-mW output power (not saturated) at a center frequency of 270-GHz. The high gain allows the amplifier to reach a moderate Power Added Efficiency (PAE) of 5.25% at the highest drive power. The results in this paper are the highest reported output powers achieved from a solid state amplifier at these frequencies, and were achieved with a high f <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">MAX</inf> InP HEMT process.