Electrical engineering

Physics

Topology (electrical circuits)

Power dividers and directional couplers

Wideband

Mathematics

CMOS

Modulation (music)

Engineering

Amplifier

Power (physics)

Acoustics

RF power amplifier

Electronic engineering

Adjacent channel power ratio

Adjacent channel

Quantum mechanics

IEEE Transactions on Microwave Theory and Techniques

This article presents a technique for load-modulated balanced amplifiers (LMBAs) to achieve a continuum of load modulation (LM) ratio. This has been possible in prior arts using asymmetrical auxiliary devices. In contrast, the proposed technique employs identical auxiliary devices. A LM ratio is enabled by a specific coupling factor of the power-combining coupler at the output. The proposed LMBA technique is demonstrated through the design, implementation, and measurement of a concurrent wideband LMBA operating across 3.1–4.2 GHz. The prototype achieves a peak output power of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$ 48.1\pm 0.6~\text {dBm}$ </tex-math></inline-formula> , with drain efficiency of 47–58% at peak power and 47–61% at 10-dB power back-off. The concurrent wideband performance is demonstrated by a characterization with 900-MHz new radio (NR) signal with 10-dB peak-to-average power ratio (PAPR). At 37.8 dBm of average output power, the measurement yields 44% drain efficiency and −44-dBc adjacent channel leakage ratio (ACLR).

Symmetrical Load Modulated Balanced Power Amplifier With Asymmetrical Output Coupling for Load Modulation Continuum