A Wideband RF Power Amplifier in 45-nm CMOS SOI Technology With Substrate Transferred to AlN

A wideband radio frequency power amplifier (RF PA) is implemented with a stack of 16 low-breakdown-voltage thin-oxide transistors in a standard 45-nm CMOS SOI technology. A combination of dynamic-biasing and stacking prevents all breakdown mechanisms when the PA operates under large voltage swings and facilitates an output impedance close to 50 Ω without a need for an output-matching network. Using a post-fabrication process, the conductive Si substrate of the CMOS SOI PA is etched away and replaced by a semi-insulating aluminum nitride (AlN) substrate to reduce the effect of substrate parasitic capacitances and improve the PA's performance. A small-signal gain of 12.2 dB at 1.8 GHz is achieved with a - 3-dB bandwidth from 1.5 to 2.6 GHz. For high-reliability operation, the PA is biased with a 15-V power supply and a small transistor current density of 0.2 mA/μm and delivers a saturated output power (PSAT) of 30.2 dBm and a peak power-added efficiency (PAE) of 23.8%. For a wide range of measured frequencies from 1.5 to 2.4 GHz and under a lower supply voltage of 12 V, PSAT and P1 dB remain above 27.9 and 24.8 dBm, respectively, with peak PAE above 20%. In terms of output power, efficiency, and linearity, the CMOS PA on AlN substrate outperforms its Si counterpart, while both PAs deliver good power performance despite utilizing thin-oxide low-breakdown-voltage transistors.

[1]  Saeed Mohammadi,et al.  Millimeter-wave power amplifiers in 45nm CMOS SOI technology , 2011, IEEE 2011 International SOI Conference.

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

[3]  Thomas H. Lee,et al.  The Design of CMOS Radio-Frequency Integrated Circuits: RF CIRCUITS THROUGH THE AGES , 2003 .

[4]  Huei Wang,et al.  A High-Efficiency, Broadband CMOS Power Amplifier for Cognitive Radio Applications , 2010, IEEE Transactions on Microwave Theory and Techniques.

[5]  J. G. McRory,et al.  Transformer coupled stacked FET power amplifiers , 1999 .

[6]  Huei Wang,et al.  Design and Analysis of Stacked Power Amplifier in Series-Input and Series-Output Configuration , 2007, IEEE Transactions on Microwave Theory and Techniques.

[7]  P. Reynaert,et al.  A Fully Integrated Watt-Level Linear 900-MHz CMOS RF Power Amplifier for LTE-Applications , 2012, IEEE Transactions on Microwave Theory and Techniques.

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

[9]  R. Negra,et al.  A Fully Integrated Adaptive Multiband Multimode Switching-Mode CMOS Power Amplifier , 2012, IEEE Transactions on Microwave Theory and Techniques.

[10]  Jan-Erik Mueller,et al.  A 1.8GHz wide-band stacked-cascode CMOS power amplifier for WCDMA applications in 65nm standard CMOS , 2011, 2011 IEEE Radio Frequency Integrated Circuits Symposium.

[11]  Bruce A. Wooley,et al.  A stacked 6.5-GHz 29.6-dBm power amplifier in standard 65-nm CMOS , 2010, IEEE Custom Integrated Circuits Conference 2010.

[12]  Songcheol Hong,et al.  A Wideband Transformer-Coupled CMOS Power Amplifier for $X$-Band Multifunction Chips , 2011, IEEE Transactions on Microwave Theory and Techniques.

[13]  Jinho Jeong,et al.  A Watt-Level Stacked-FET Linear Power Amplifier in Silicon-on-Insulator CMOS , 2010, IEEE Transactions on Microwave Theory and Techniques.

[14]  P. Asbeck,et al.  A 20 dBm Linear RF Power Amplifier Using Stacked Silicon-on-Sapphire MOSFETs , 2006, IEEE Microwave and Wireless Components Letters.

[15]  Bumman Kim,et al.  A 30.8-dBm Wideband CMOS Power Amplifier With Minimized Supply Fluctuation , 2012, IEEE Transactions on Microwave Theory and Techniques.

[16]  Saeed Mohammadi,et al.  A 1.8GHz stacked power amplifier in 45nm CMOS SOI technology with substrate-transferred to AlN , 2012, 2012 IEEE/MTT-S International Microwave Symposium Digest.