Abstract:

Phased arrays have originally only been used for military applications due to their high cost and system sophistication. Recently, there is high demand for low cost phased arrays both in military and commercial sectors. In general, there are two categories of phased arrays: analog and digital phased arrays. Analog phase shifters (either continuous or step phase shifters) have been used to dynamically provide the proper excitation coefficients for antenna elements. Then all the signals will be combined and delivered to the frontend. In contrast with this technique, digital phased arrays use separate receiving paths for each individual antenna element all the way to the digital domain. The beam forming will be performed in the digital domain.

The benefit of an analog phased array is its ability to overcome jamming by rejecting the jamming signal using the space filtering property of the phased array before the front end unit. Digital phased arrays don’t have lossy, expensive phase shifters but the number of receiving paths can be a challenge for arrays with a large number of elements. We are proposing a novel technique which uses one receiving path for all elements while it performs the beam forming in the digital domain. This new technique reduces the complexity and cost of a phased array for both military and commercial applications.

Speaker:  

Dr. Majid Manteghi is an assistant professor in Electrical and Computer Engineering at Virginia Tech since Sept. 2007. Dr. Manteghi received a Ph.D. in Electrical and Computer Engineering from University of California, Los Angeles, in 2005. Before joining Virginia Tech, he held industrial positions as a research scientist at Mojix Inc. and developed RF systems and phased arrays for RFID readers.

His Ph.D work was on Impulse Radiating Antennas (IRAs), where he also worked on MIMO antennas, miniaturized antennas, and time domain measurement techniques. Prior to joining UCLA, he worked for a company and developed RF systems and circuits and antennas for a GSM900 base transceiver station (BTS). Dr. Manteghi’s research interests include time-domain and frequency-domain electromagnetics theory, nonlinear time variant techniques in antenna design, chipless RFID and time-frequency target identification techniques, wireless power transfer, and phased array design.