상세정보
학술지
CMOS Doherty Amplifier With Variable Balun Transformer and Adaptive Bias Control for Wireless LAN Application
- 발행일
- 201406
- 출처
- IEEE Journal of Solid-State Circuits, v.49 no.6, pp.1356-1365
- ISSN
- 0018-9200
- 출판사
- IEEE
- 협약과제
- 13VI1600, 차세대 이동통신 기지국용 Class-S 전력증폭기 기술 연구, 정재호
- 초록
- This paper presents a novel CMOS Doherty power amplifier (PA) with an impedance inverter using a variable balun transformer (VBT) and adaptive bias control of an auxiliary amplifier. Unlike a conventional quarter-wavelength {\\lambda}/4 transmission line impedance inverter of a Doherty PA, the proposed VBT impedance inverter can achieve load modulation without any phase delay circuit. As a result, a {\\lambda} /4 phase compensation circuit at the input path of the auxiliary amplifier can be removed, and the total size of the Doherty PA can be reduced. Additionally, an enhancement of the power efficiency at backed-off power levels can successfully be achieved with an adaptive gate bias in a common gate stage of the auxiliary amplifier. The PA, fabricated with 0.13-μm CMOS technology, achieved a 1-dB compression point (P1 dB) of 31.9 dBm and a power-added efficiency (PAE) at P1 dB of 51%. When the PA is tested with 802.11g WLAN orthogonal frequency division multiplexing (OFDM) signal of 54 Mb/s, a 25-dB error vector magnitude (EVM) compliant output power of 22.8 dBm and a PAE of 30.1% are obtained, respectively. © 1966-2012 IEEE.
- KSP 제안 키워드
- 1-dB compression point, Adaptive bias, Bias control, CMOS Technology, Compensation circuit, Delay circuit, Doherty PA, Doherty amplifier, Doherty power amplifier(DPA), Line Impedance, Orthogonal frequency division Multiplexing(OFDM)