A Continuous-Mode Class- $\mathrm{F}^{-1} \mathrm{X}$-Band Gan Mmic Power Amplifier with a 29.7

This paper presents a high-performance X-band continuous-mode Class- <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\mathrm{F}^{-1}$</tex> MMIC power amplifier (PA) in <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$0.25 \mu \mathrm{m}$</tex> GaN technology. Design considerations and challenges of continuous-mode Class- <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\mathrm{F}^{-1}\left(\text{CCF}^{-1}\right)$</tex> have been discussed. Broadband matching networks with low losses are designed by accounting for varying optimal impedances at different frequencies and power levels with minimal components. Measured results show the <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\text{CCF}^{-1} \text{PA}$</tex> achieving <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$P_{\text {sat}}$</tex> of 37.4 dBm, with a peak PAE of 44.3 %, and a gain of 21.2 to 24 dB in the <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$f_{-3 \text{dB}}$</tex> from 8.3 to <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$11.2 \text{GHz}(29.7 \%)$</tex>. Performance evaluation using a 5G NR FR1 <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$256-\text{QAM} 100-\text{MHz}$</tex> bandwidth modulated signal yields an average <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$P_{\text {out}}$</tex> of 31.3 dBm, meeting the 3.5 % error vector magnitude (EVM) requirement. Compared to the previously published <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$0.25-\mu \mathrm{m}$</tex> GaN MMICs with harmonic tuning in a similar frequency range, this work achieves the largest fractional bandwidth, and the FoMs are among the best.