Home > Seminars > Millimeter Wave Technologies for Linear, Efficient, and Agile Communications Systems

Millimeter Wave Technologies for Linear, Efficient, and Agile Communications Systems

Start:

5/5/2014 at 2:00PM

End:

5/5/2014 at 3:00PM

Location:

258 Fitzpatrick Hall

Host:

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Thomas Fuja

Thomas Fuja

VIEW FULL PROFILE Email: tfuja@nd.edu
Phone: 574-631-7244
Office: 275 Fitzpatrick Hall

Affiliations

Wireless Institute Professor
Prof. Fuja research addresses reliable communication over inherently unreliable and/or constrained communication links. He has recently focused his research on the changing role that channel codes play in the context of wireless networks, i.e., to not only provide physical-layer robustness but ...
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The past generation of wireless communications systems, whether they be for the commercial or the military sector, have continued to follow an exponential growth in throughput. In order to keep pace with the demand, modulation schemes have increased in complexity requiring more linear hardware to comply with spectrum masks and enable reliable adjacent channel communications. Military platforms require even more linearity for simultaneous operation of high power radar and high fidelity communications in the presence of intentional interferers. In addition, a continuous desire to reduce size, weight and power motivates multifunction systems-on-chip. As the Wi-Fi standard anticipates a move to 60 GHz (802.11ad) to take advantage of the many GHz of contiguous spectrum, and military radars move into the millimeter wave bands currently occupied by satellite communications, future multifunction apertures will need to operate in the millimeter wave bands from 20-60 GHz. Finally, the concept of “white-space” communications and frequency hopping and anti-jam military communications require frequency agile hardware. This talk discusses the technologies required to achieve a highly linear, power efficient, and wideband frequency-agile phased array capable of synthesizing 2 GHz of instantaneous bandwidth anywhere in the 18-45 GHz band. The core of the system is a low-power 2 GHz DAC and wideband SiGe RFIC up-converter and amplifier. Linear and nonlinear digital compensation methods provide additional signal fidelity to enable multifunction operation in adjacent channels. Multi-chip modules require novel baluns and matching networks, as well as custom waveguides and antennas to operate over multiple octaves of bandwidth. As digital back-ends move closer to the RF front-end there is an inherent trade between analog and digital complexity and power to achieve the given system requirements. We will discuss the co-design of this analog/digital system to achieve simultaneously low-power and linear operation.

Seminar Speaker:

Jonathan Chisum

Jonathan Chisum

MIT Lincoln Laboratory

Jonathan D. Chisum received the B.S. degree in electrical engineering from Seattle Pacific University, Seattle, WA, in 2003, and the M.S. and Ph.D. degrees in electrical engineering from the University of Colorado at Boulder in 2008 and 2011. He is currently a Member of the Technical Staff at MIT Lincoln Laboratory in the Wideband Tactical Networking group. Jonathan’s current research is in passive and active circuits for millimeter-wave communications systems. He is particularly interested in the combination of analog circuits and digital compensation methods to achieve unprecedented performance in bandwidth and linearity. Currently, he is designing a SiGe-based digital phased array with efficient, linear operation from 18-45 GHz. Jonathan is a member of the IEEE MTT-S and AP-S, as well as the AIP. He was the recipient of the NIST Professional Research Experience Program (PREP) grant from 2006-2008, and in 2009 was a Research Intern at the VTT Technical Research Center of Finland. During this time Jonathan worked on THz imaging systems including ultrawideband antennas and low-noise electronics. From 2008 to 2011 he was partially funded by an MIT Lincoln Laboratory Fellowship to develop a near-field microwave microscopy system for sub-surface detection of materials and devices with sub-micron resolution. Since joining the staff at MIT Lincoln Laboratory, he has led a team to investigate practical applications for RF metamaterials. This effort is developing wideband, low loss non-Fosters circuit for inclusion in metamaterial unit cells to mitigate the narrowband and lossy performance that has so far hindered its adoption in practical systems.