SDR Transmitters: Analog or Digital?

May 31, 2013
2:00pm-3:00pm
633 Mudd
Hosted by: Columbia Integrated System Laboratory
Speaker: Dr. Jan Craninckx (IMEC)

Abstract

Flexibility and reconfigurability are the new keywords in RF design, several applications require transceivers operating in different modes to fulfill market requirements. Recent research has shown two very different trends. Classical analog-inspired architectures focus on performance numbers that are on par with dedicated radios, using circuits and techniques that offer programmability at low (or no) cost. Digital-intensive approaches offer flexibility for free, but even more important are not limited by the analog performance bottlenecks in new technology nodes.

This presentation will give an overview of several examples in this field, with a focus on their respective possibilities and limitations. The analog voltage-sampling transmitter is a key enabler for the tough out-of-band noise requirements in cellular systems. Extension with harmonic-rejection techniques allow is also the tackle the linearity counter-IM3 issue in LTE systems. On the digital side, both polar and cartesian (I/Q) direct digital RF modulators (DDRM) are published, that take the functionality of an RF DAC. FIR-based filtering is proposed to lower RX-band noise below the quantization noise, and a Doherty architecture tackles the efficiency for high output powers.

Speaker Biography

Jan Craninckx obtained his Ms. and Ph.D. degree in microelectronics summa cum laude from the ESAT-MICAS laboratories of the Katholieke Universiteit Leuven in 1992 and 1997, respectively. His Ph.D. work was on the design of low-phase noise CMOS integrated VCOs and synthesizers. From 1997 till 2002 he worked with Alcatel Microelectronics (later part of STMicroelectronics) as a senior RF engineer on the integration of RF transceivers for GSM, DECT, Bluetooth and WLAN. In 2002 he joined IMEC (Leuven, Belgium), where he currently is the senior principal scientist of the analog wireless research group. His research focuses on the design of RF transceiver front-ends for software defined radio (SDR) systems, covering all aspects of RF, analog and data converter design.

Dr. Craninckx has authored and co-authored more than 100 papers and several book chapters, and is the inventor of 10 patents. He is a member of the Technical Program Committee for the several conferences, was the chair of the SSCS Benelux chapter (2006-2011), and is an Associate Editor of the JSSC.


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