IEEE MTT/AP Chapter Presents

" Techniques in Multi-band/Multi-standard Doherty Power Amplifiers for Wireless Transmitters"

Presented by Dr. Karun Rawat

Center for Applied Research in Electronics, Indian Institute of Technology Delhi, India

Date: 3:00 PM - 4:00 PM   Wednesday, November 13, 2013

Place: Dreese Laboratories, Room DL 260, 2015 Neil Ave, Columbus, OH 43210

Abstract: The upcoming business opportunities in the strategic area of wireless and satellite communications have triggered many new areas of research in terms of wireless standards, protocols, as well as RF design.  In particular, spectral efficient modulation schemes and multiple accesses techniques with broadband communication signals present several challenges to the RF community especially related to transmitter design. In the presence of such signals, nonlinear components in transmitters such as power amplifiers (PA) has to be operated at certain back-off from saturation exhibiting low efficiency and high nonlinearity. In such scenario, efficiency enhancement techniques such as Doherty PA are attractive but require extension towards multi-band/multi-mode operation.  Moreover, digital-RF co-design approach is also required to optimize the wireless transmitters for simultaneously high energy and spectral efficiency. 

This talk is presenting design and implementation perspective of multi-band/multi-mode transmitter architecture using multi-band Doherty PA for efficiency enhancement. A design strategy for multi-band passive and active components is also discussed.  The talk will conclude with an idea of broad-band Doherty load combiner which can be used in N-way and N-stage Doherty PA architecture.

Bio:  Dr. Karun Rawat received his PhD. degree in Electrical Engineering from University of Calgary Canada in 2012. He is currently Assistant Professor in Centre for Applied Research in Electronics (C.A.R.E), Indian Institute of Technology Delhi. Before this, he worked as scientist in the Space Applications Center, Indian Space Research Organization (ISRO) Ahmedabad, from 2003–2007, where he was involved in the design and development of microwave receivers for remote sensing applications. His current research interests are in the areas of nonlinear circuit design for power amplification and multi-band/multi-mode advanced concurrent transmitter architecture for software defined radio applications. His research involvement has resulted in more than 27 publications in journals and conferences with 18 in IEEE society. He is currently senior member of IEEE. Due to his active research activities and publications, he has been recipient of research production award for the three consecutive years from 2009-2012 by University of Calgary. Under his leadership, University of Calgary team won first prize as well as the best design award in the 3rd Annual Smart Radio Challenge 2010 conducted by Wireless Innovation forum while competing against five universities from U.S. and Japan.