The Path to the Software-Defined Radio Receiver

• Published in: IEEE journal of solid-state circuits Vol. 42; no. 5; pp. 954 - 966
• Main Author: Abidi, A.A.
• Format: Journal Article
• Language: English
• Published: New York IEEE 01.05.2007; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Amplifiers; Analog decimator; analog FIR filter; anti-aliasing; bandpass signal processing; Bandwidth; Baseband; boxcar integrator; Broadband amplifiers; Cell phones; Channels; Clocks; cognitive radio; Conversion; decimation; digital AGC; Digital filters; direct conversion receiver; Filtering; Low-noise amplifiers; Mixers; Mobile handsets; multi-mode receiver; multi-rate signal processing; Radio frequency; Radio receivers; receiver dynamic range; Receivers; sampling; Software Defined Radio (SDR); switched capacitor circuit; wide tuning local oscillator; Wideband; wideband receiver; wideband sampling; zero IF
• ISSN: 0018-9200; 1558-173X
• DOI: 10.1109/JSSC.2007.894307

After being the subject of speculation for many years, a software-defined radio receiver concept has emerged that is suitable for mobile handsets. A key step forward is the realization that in mobile handsets, it is enough to receive one channel with any bandwidth, situated in any band. Thus, the front-end can be tuned electronically. Taking a cue from a digital front-end, the receiver's flexible analog baseband samples the channel of interest at zero IF, and is followed by clock-programmable downsampling with embedded filtering. This gives a tunable selectivity that exceeds that of an RF prefilter, and a conversion rate that is low enough for A/D conversion at only milliwatts. The front-end consists of a wideband low noise amplifier and a mixer tunable by a wideband LO. A 90-nm CMOS prototype tunes 200 kHz to 20-MHz-wide channels located anywhere from 800 MHz to 6 GHz