A broadband GaAs high power millimeter wave amplifier with high gain and flatness

Abstract

This paper presents a broadband millimeter-wave power amplifier with a combination of 2-way, each of which consist of a distributed amplifier and cascaded single-ended stages for high gain and output power. To the best of our knowledge, it is the first time that the two amplifiers based on a distributed stage and cascaded single-ended stages have been combined for high power. As a result, the saturated power is improved up to more than 20.5 dBm in the frequency band of 33–66 GHz. Meanwhile, by combining distributed amplifier and cascaded single-ended stages methods, the power amplifier has inherent advantages of high gain and wide bandwidth. Moreover, to improve the gain flatness, small resistor-capacitors in bias circuits are introduced in the cascaded single-ended stages amplifier structure, so the measured S21 is improved to 21.8 ± 0.6 dB in the 38–67 GHz band. These results show that high gain with good flatness and power can be achieved using the proposed method.