A Fully Integrated Watt-Level Linear 900-MHz CMOS RF Power Amplifier for LTE-Applications

There is a growing demand for the implementation of the RF power amplifier (PA) in CMOS technologies, due to its cost and integration benefits. Most of the already reported CMOS PAs do not have sufficient output power nor linearity to cope with the long term evolution (LTE) requirements. In this paper, the linearity requirements for power amplifiers targeting LTE-applications are investigated. Based on this system level analysis, a single-chip fully integrated CMOS power amplifier with sufficient power and linearity for emerging E-UTRA/LTE-applications is designed. This 90-nm LTE-band VIII CMOS linear power amplifier uses a distributed active transformer (DAT) as power combiner and delivers an output power up to 29.4 dBm with 25.8% power-added efficiency (PAE) and has 28-dB small-signal gain. The choice of optimal biasing ensures a very flat gain and small AM-PM distortion up to high output power. While applying an uplink LTE signal, the PA produces 25 dBm of average output power with 15% PAE while obeying the stringent EVM-specifications.

[1]  D. Rutledge,et al.  An optimized design of distributed active transformer , 2005, IEEE Transactions on Microwave Theory and Techniques.

[2]  Ali Hajimiri,et al.  Distributed active transformer-a new power-combining and impedance-transformation technique , 2002 .

[3]  Songcheol Hong,et al.  A fully-integrated 900-MHz CMOS power amplifier for mobile RFID reader applications , 2006, IEEE Radio Frequency Integrated Circuits (RFIC) Symposium, 2006.

[4]  Ali Hajimiri,et al.  A Fully-Integrated Quad-Band GSM/GPRS CMOS Power Amplifier , 2008, IEEE Journal of Solid-State Circuits.

[5]  Lawrence E. Larson,et al.  A 65nm CMOS 2.4GHz 31.5dBm power amplifier with a distributed LC power-combining network and improved linearization for WLAN applications , 2010, 2010 IEEE International Solid-State Circuits Conference - (ISSCC).

[6]  Ali Hajimiri,et al.  A 2.4-GHz, 2.2-W, 2-V fully-integrated CMOS circular-geometry active-transformer power amplifier , 2001, Proceedings of the IEEE 2001 Custom Integrated Circuits Conference (Cat. No.01CH37169).

[7]  Yan Li,et al.  A SiGe Envelope-Tracking Power Amplifier With an Integrated CMOS Envelope Modulator for Mobile WiMAX/3GPP LTE Transmitters , 2011, IEEE Transactions on Microwave Theory and Techniques.

[8]  Lawrence E. Larson,et al.  An integrated 33.5dBm linear 2.4GHz power amplifier in 65nm CMOS for WLAN applications , 2010, IEEE Custom Integrated Circuits Conference 2010.

[9]  Patrick Reynaert,et al.  A fully integrated CMOS power amplifier for LTE-applications using clover shaped DAT , 2011, 2011 Proceedings of the ESSCIRC (ESSCIRC).

[10]  Paul R. Gray,et al.  A 1.9-GHz, 1-W CMOS class-E power amplifier for wireless communications , 1999 .

[11]  J. Dekosky,et al.  SiGe power amplifier ICs for 4G (WIMAX and LTE) mobile and nomadic applications , 2010, 2010 IEEE Radio Frequency Integrated Circuits Symposium.

[12]  Joy Laskar,et al.  Analysis and Design of Fully Integrated High-Power Parallel-Circuit Class-E CMOS Power Amplifiers , 2010, IEEE Transactions on Circuits and Systems I: Regular Papers.

[13]  Ali Hajimiri,et al.  Fully integrated CMOS power amplifier design using the distributed active-transformer architecture , 2002, IEEE J. Solid State Circuits.

[14]  H. Zirath,et al.  A comprehensive analysis of IMD behavior in RF CMOS power amplifiers , 2004, IEEE Journal of Solid-State Circuits.

[15]  Ali M. Niknejad,et al.  A single-chip highly linear 2.4GHz 30dBm power amplifier in 90nm CMOS , 2009, 2009 IEEE International Solid-State Circuits Conference - Digest of Technical Papers.

[16]  Atila Alvandpour,et al.  A +32 dBm 1.85 GHz class-D outphasing RF PA in 130nm CMOS for WCDMA/LTE , 2011, 2011 Proceedings of the ESSCIRC (ESSCIRC).