Our goals are to develop innovative circuit techniques and RF to THz ICs for emerging wireless and wireline communications and radar systems. We have demonstrated a number of ICs up to 500 GHz. Our DMRC faculty group works on a variety of semiconductor technologies including InP, GaN, GaAs, Si, SOI, and SiGe. We are currently developing RF and THz integrated circuits for applications including emerging wireless communications (5G and 6G), chip-to-chip communications, fusion plasma diagnostics, phased-array antennas, and radar systems.
RF to THz Circuits
Millimeter-wave to THz Imaging
Millimeter wave and THz imaging are proving to be valuable adjuncts to visible, IR, and X-ray imaging systems. The advantage of millimeter wave radiation is that, in addition to clear weather day and night operation, it can also be used in low visibility conditions such as in smoke, fog, clouds and even sandstorms. In this way, millimeter wave imaging expands our vision by letting us “see” things under poor visibility conditions. With this extended vision ability, a wide range of military imaging missions would benefit, such as surveillance, precision targeting, navigation, search and rescue. In the commercial realm, aircraft landing aids, airport operations, and highway traffic monitoring in fog can also benefit from MMW imaging. For security concerns, concealed weapon and explosives detection in airports and other locations can be aided with several passive as well as active MMW imaging techniques. In addition, millimeter wave imaging is also applied in remote sensing, radio astronomy, and plasma diagnostics to visualize objects that cannot be directly seen. Millimeter wave imaging can basically be divided into two separate approaches: passive millimeter wave imaging and active millimeter wave imaging. Passive millimeter wave systems directly detect the natural radiation from the objects or the reflection from the environment. The concept is analogous to radiometry. Active millimeter wave imaging systems first illuminate the objects and subsequently detect the reflected millimeter waves. Many active imaging systems are essentially radar based.
Millimeter-wave to THz Vacuum Electronics
Terahertz (THz) waves (~0.1 to 10 THz) have tremendous potential for applications including ultra-fast (femto-second) phenomena studies, high-data-rate communication networks, tumor/cancer scans, living cell imaging (4D-tomography), nondestructive device inspection, hydrodynamics analysis, nano-compound spectroscopy, and sub-wavelength microscopy / lithography. However, the most critical problem is the absence of an appropriate watt-level radiation source, which can provide several orders of magnitude signal-to-noise ratio with broad spectral coverage. Recently, micro vacuum electron devices (µVEDs) have received considerable attention as a possible breakthrough for high power THz source development owing to their high energy conversion efficiency and large thermal power capacity. This approach requires linear scale-down of bulky VED elements, which is made possible by advances in micro-fabrication technology which have opened the way to miniaturize bulky vacuum electronic circuits down to the sub-millimeter scale, which enables the development of portable THz radiation sources. In the DMRC, we have developed UV lithographic microelectroforming techniques for the fabrication of the required ultra-thick metallic microstructures ( >= 400 mm) with sidewall surface roughness of ~ 50 – 100 nm.
At the DMRC, we focus on developing radar, sensor and communications systems for several sectors including wireless and wireline communications, fusion energy, agriculture, biomedical diagnostics, security and surveillance, and imaging. Our radar, sensor, and communications research have several thrusts. 1) We demonstrate the capabilities to develop a full radar and sensor system with computerized software for application deployment. 2) We are developing a number of system-on-chip and important chip-sets to build radar, sensor, and communication systems. 3) We deploy commercially available radar in usage applications where we develop signal processing algorithms and use machine learning to interpret and analyze data.
Radar, Sensor and Communications System
Our applied electromagnetics research includes antennas and radio wave propagation, electronic packaging, micro-electromechanical systems, passive components, metamaterials, micro/nano-scale, metasurface configurations, and 2-D materials such as graphene. Our efforts aim to overcome the limitation of current communication, radar, and sensing systems in terms of dynamic reconfiguration, integration and miniaturization while simultaneously boosting their performance and functionalities. We develop devices, circuits, antennas and systems from RF to THz frequencies.
Applied Electromagnetics