A highly-efficient BiCMOS cascode Class-E power amplifier using both envelope-tracking and transistor resizing for LTE-like applications

Author

Li, Yan ; Wu, Ruili ; Lopez, Jerry ; Lie, Donald Y C

Author_Institution

Dept. of Electr. & Comput. Eng., Texas Tech Univ., Lubbock, TX, USA

fYear

2011

fDate

9-11 Oct. 2011

Firstpage

142

Lastpage

145

Abstract

This paper presents the design of a SiGe differential cascode power amplifier (PA) to perform the envelope-tracking (ET) along with transistor resizing for efficiency enhancement for the 16QAM LTE. A new parallel-circuit class-E PA model is developed to analyze and design the cascode PA. The analytic results are compared with SPICE simulation and measurement data to provide circuit design insights. Measurement shows the ET-based PA system reaches an overall power-added-efficiency (PAE) of 38% at its 1 dB compression point (P_1dB) of 22 dBm for its high power mode. Additionally, at the low power mode, some of the transistor cells can be disabled by the integrated MOSFET switches, and the overall PAE is improved by 4-5% at ≥4 dB back-off from its P_1dB. This ET-based cascode PA satisfies the LTE 16QAM linearity specs without needing predistortions.

Keywords

BiCMOS analogue integrated circuits; Ge-Si alloys; Long Term Evolution; field effect transistor switches; power amplifiers; quadrature amplitude modulation; 16QAM LTE; ET-based PA system; LTE-like applications; Long-Term-Evolution; PAE; SPICE measurement data; SPICE simulation; SiGe; circuit design; differential cascode power amplifier; efficiency 38 percent; envelope-tracking; highly-efficient BiCMOS cascode Class-E power amplifier; integrated MOSFET switches; parallel-circuit class-E PA model; power-added-efficiency; transistor cells; transistor resizing; BiCMOS integrated circuits; CMOS integrated circuits; Linearity; Modulation; Power amplifiers; Silicon germanium; Transistors; LTE; SiGe BiCMOS power amplifier (PA); envelope-tracking (ET); parallel-circuit class-E PA model; transistor resizing;

fLanguage

English

Publisher

ieee

Conference_Titel

Bipolar/BiCMOS Circuits and Technology Meeting (BCTM), 2011 IEEE

Conference_Location

Atlanta, GA

ISSN

1088-9299

Print_ISBN

978-1-61284-165-6

Type

conf

DOI

10.1109/BCTM.2011.6082767

Filename

6082767