A Low-Noise and Highly-Linear Transmitter with Envelope Injection Pre-Power Amplifier for Multi-Mode Radio

Shouhei KOUSAI  Daisuke MIYASHITA  Junji WADATSUMI  Rui ITO  Takahiro SEKIGUCHI  Mototsugu HAMADA  Kenichi OKADA  

IEICE TRANSACTIONS on Fundamentals of Electronics, Communications and Computer Sciences   Vol.E94-A   No.2   pp.592-602
Publication Date: 2011/02/01
Online ISSN: 1745-1337
DOI: 10.1587/transfun.E94.A.592
Print ISSN: 0916-8508
Type of Manuscript: Special Section PAPER (Special Section on Analog Circuit Techniques and Related Topics)
multi-mode radio,  wideband transmitter,  active matching,  envelope injection,  

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A wideband, low noise, and highly linear transmitter for multi-mode radio is presented. Envelope injection scheme with a CMOS amplifier is developed to obtain sufficient linearity for complex modulation schemes such as OFDM, and to achieve low noise for concurrent operation of more than one standard. Active matching technique with doubly terminated LPF topology is also presented to realize wide bandwidth, low power consumption, and to eliminate off-chip components without increasing die area. A multi-mode transmitter is implemented in a 0.13 µm CMOS technology with an active area of 1.13 mm2. Third-order intermodulation product is improved by 17 dB at -3 dBm output by the envelope injection scheme. The transmitter achieves EVM of less than -29.5 dB at -3 dBm output from 0.2 to 7.2 GHz while consuming only 69 mW. The transmitter is also tested with multiple standards of UMTS, 802.11b, WiMax, 802.11a, and 802.11n, and satisfies EVM, ACLR, and spectrum specifications.