A 10-W High-Power Amplifier Using Input Nonlinearity for <i>K</i>-Band Satcom Applications

Abstract

This letter presents a <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${K}$ </tex-math></inline-formula> -band 0.1- <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\mu \text{m}$ </tex-math></inline-formula> GaN on Si 10-W high-power amplifier (HPA) for the downlink of the satellite <bold xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">communication</b> system. The proposed HPA uses the driver-stage transistor to generate a half-sinusoidal waveform that is delivered to the power-stage transistor. The half-sinusoidal waveform combines the input nonlinearity of the power-stage transistor to simultaneously improve the efficiency and expand the design space of the input harmonic impedance. A simple and compact interstage matching network (ISMN) design is used to match the harmonic impedance of both driver and power-stage transistors to create the corresponding waveforms. The proposed HPA has a small size of 3.5 mm <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\times3.2$ </tex-math></inline-formula> mm and operates in the frequency range of 17–20.5 GHz achieving a 22-dB gain, an average 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">${P}_{\mathbf {out}}$ </tex-math></inline-formula> ) of 42 dBm, and 41% power-added efficiency (PAE) in the pulsed measurement. Moreover, the proposed HPA maintains a PAE of more than 33% and output power of 40.4 dBm in continuous wave (CW) measurement.