A High Efficiency Ka Band Power Amplifier for Millimeter Wave Communication Systems

This paper presents a high efficiency MMIC PA with a two stage and four-way combined topology. The proposed PA operating at Ka band is designed to get high efficiency and high gain over 37 dBm and employed 0.12 um GaN-on-SiC process. The Ka band PA is presented for potential integration into millimeter wave communication applications, such as 5 G and satellite communication systems. A two-way <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$8 \times 75$</tex> um gate width device was used to develop the driving stage of the proposed PA, and the output stage used four way <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$8 \times 100$</tex> um gate width device. The proposed PA achieves 37.21 dBm to 38.56 dBm of output power from 26.5 GHz to 28.5 GHz with a peak power addition efficiency (PAE) greater than <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$30.68 \%$</tex> when operating at 28 V. The designed PA demonstrates a high small signal gain of 15.88 dB to 20.20 dB with a small chip size of <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$3.72 \times 2.65 ~\text{mm}^{2}$</tex>. Besides, stabilizing technique has been used to make the designed PA unconditionally stable in the whole frequency band from DC to 50 GHz.