2.6- and 4-W E-Band GaN Power Amplifiers With a Peak Efficiency of 22% and 15.3%

Abstract

In this letter, we report two high-power gallium nitride (GaN) power amplifiers (PAs) in the Satcom <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$E$ </tex-math></inline-formula> -band (71–86 GHz) with an output power of 2.6 and 4 W, designed by incorporating an ultralow-loss ON-chip integrated power combiner. The first one is a three-stage four-way combining (unit) PA, and the second one is an eight-way combining balanced PA. The unit PA produces a saturated output power ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$P_{\mathrm{SAT}}$ </tex-math></inline-formula> ) of 34.2 dBm (2.6 W), a peak power-added-efficiency (PAE) of 22%, and an associated power gain of 16.2 dB at 74 GHz. This performance was partly made possible by the design and optimization of the low-loss integrated power combiner, which minimized the losses in the matching networks. In addition, the balanced PA produces a <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$P_{\mathrm{SAT}}$ </tex-math></inline-formula> of 36 dBm (4 W), <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$P_{\text {1 dB}}$ </tex-math></inline-formula> of 35.6 dBm (3.63 W), with an associated PAE of 15.3% at 80 GHz. To the best of the authors’ knowledge, this is the highest output power (4 W) and the highest PAE (22%) for a PA > 2.5 W reported in any of the III–V technologies at <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$E$ </tex-math></inline-formula> -band.