Abstract:

Phased arrays have been widely used for defense applications at a high cost per element ($200-2000). Recently, phased arrays have expanded into other application areas such as mm-wave (60 GHz) high data-rate communication systems and scanned 24 GHz imaging systems. There has been intensive effort to reduce the cost of phased arrays for both defense and commercial applications, which has been accomplished mainly by integrating them in silicon technologies.

This talk focuses on silicon-based phased-array receiver and transmitter designs at microwave (6-18 GHz) and mm-wave frequencies (40-50 GHz), which have played a major role in leading the industry toward a low cost path. The phase shifter is the most critical building block in a phased array, and, therefore, the first part focuses on the recent advancements in phase shifter designs. The second part presents analysis, design and measurements of an 8-element 6-18 GHz phased-array receiver at the silicon-IC level and the antenna- board level, and verification at the first system-level. The third part presents mm-wave (40-50 GHz) phased-array transmitter (16 elements) and receiver designs, which are one of the most complex integrated phased-array systems in silicon technology. Most of the designs presented in the talk have been successfully transferred to the US defense industry.

Speaker:  

Dr. Kwang-Jin Koh is an assistant professor in Electrical and Computer Engineering at Virginia Tech since Nov. 2011. Dr. Koh received a Ph.D. in Electrical and Computer Engineering from University of California, San Diego, in 2008. Before joining Virginia Tech, he held industrial positions of a senior and senior staff engineer at Intel and Broadcom Corp. and developed RF and analog integrated circuits for Intel microprocessors, wireless radio systems on a chip (SoC), and TV tuner systems.

Dr. Koh received the best paper award from IEEE Solid-State Circuits Society and Electron Device Society, Seoul Chapter, in 2002. His Ph.D works on integrated phased-arrays on silicon technologies have been reported to Pentagon in a DARPA War Report as one of major accomplishments in 2007. He also received Best Team of the Year Award from Teledyne Scientific Corp. (formerly Rockwell Scientific Corp.) in 2010. His major research interests include integrated radio and radar systems in silicon technologies for wireless communications, wireless sensing and detection, and imaging applications at RF, microwave, millimeter and sub-millimeter wave regimes.