Title :
Analysis and Design of Small-Signal Polar Transmitters for Cellular Applications
Author :
Darabi, Hooman ; Jensen, Henrik ; Zolfaghari, Alireza
Author_Institution :
Broadcom Corp., Irvine, CA, USA
fDate :
6/1/2011 12:00:00 AM
Abstract :
In cellular applications, open-loop small-signal polar transmitters offer several advantages such as low power consumption and small silicon area. However, due to their complexity, circuit imperfections can severely affect performance, potentially rendering them impractical to meet the challenging cellular transmitter requirements. In this paper a detailed analysis of the direct-modulated and small-signal polar transmitters for GSM/EDGE/WCMA applications are provided followed by some case studies. Several key non-idealities will be discussed and circuit level as well as architectural remedies for each will be presented. A prototype EDGE transmitter fabricated in 65 nm CMOS with an 8PSK ±400 kHz modulation spectrum of -64/63 dBc for high/low bands, and an RMS EVM of 2.5/2.0% will be discussed.
Keywords :
cellular radio; radio transmitters; cellular application; cellular transmitter requirement; modulation spectrum; open loop small signal polar transmitter; Bandwidth; GSM; Phase locked loops; Phase modulation; Phase noise; Voltage-controlled oscillators; 8PSK; EDGE; EVM; GMSK; GSM; QPSK; WCDMA; direct modulation; direct-conversion; modulation spectrum; phase error; phased locked loop; polar; small-signal polar;
Journal_Title :
Solid-State Circuits, IEEE Journal of
DOI :
10.1109/JSSC.2011.2118470
