Phased Arrays and Lenses for Low-Power 5G MMW Communications
Dr. Chisum, Department of Electrical Engineering
Phased arrays have proven to be an enabler for high-performance communications and sensing in the sub-6 GHz bands. They enable high-gain links to individual remote radios which can be tracked in space to achieve high data rates, enable spatial reuse, and even provide location-aware applications. This technology was initially developed in the defense sector at great cost and with significant power consumption. However, commercial-off-the-shelf (COTS) DACs and ADCs have seen a dramatic reduction in cost and power consumption and a wide range of integrated RF components in the sub-6 GHz bands have become available. These trends have enabled the technology to transition to the commercial sector with great success.
More recently the same technology was transitioned to the millimeter-wave (MMW) bands (>30 GHz) to enable 5G MMW communications with data rates beyond 1 Gbps. Unfortunately, the technology (data converters and radio components) did not scale well so the 5G MMW phased arrays consume extremely high power. In fact, the first generation of 5G MMW-enabled mobile phones were only capable of operating at Gbps rates for ~10 minutes before the battery was drained.
Instead of taking technologies that worked well at low-frequencies and moving them up in frequency, an alternative approach is to take technologies which natively work at high frequencies such as lens antennas, and modify them to provide the desired functionality (high-speed beam-scanning and multi-beam apertures) for 5G MMW.
The purpose of this research project is to explore the length to which switch-beam lens antennas can provide the most important features and capabilities of a phased array but at a fraction of the cost and power. This project will build off of the MMW lens antenna demonstrations from the PIs research group and will include theoretical electromagnetic antenna modeling as well as linear systems analysis (especially beam-forming theory and beam-synthesis methods from field theory).
The student will perform analysis, modeling, and simulation of both phased array systems and lens antenna systems. They will take advantage of the Matlab phased array toolbox as well as in-house models for lens antennas to perform the system-level comparison. The student will first need to attain a conceptual understanding of how phased arrays and lens antennas work. This will be done with guidance from graduate students and the PI. Then they will develop models of each.
In order to do this, the student will perform full-wave electromagnetic simulations of the antennas in question in both commercially available finite-element method (FEM) and finite-difference time-domain (FDTD) electromagnetic solvers. By the end of the summer, the student will have applied electromagnetic theory and systems analysis to the question of low-power millimeter-wave beam-scanning antennas. The outcome of the work will be an assessment of how well lens antenna systems can accomplish the same thing as phased arrays at a fraction of the power and cost.