Research
Dynamic Metamaterial Antennas
Background: Metamaterial antennas are waveguides or cavities with their upper conductors fashioned with numerous subwavelength radiators. Each radiator can be loaded with a switchable component and addressed independently. As the feed wave travels along the antenna, a small portion is radiated by each metamaterial radiator. The resulting overall patterns can be thought of as the superposition of the field due to all the metamaterial elements. By tuning the switchable components loading metamaterial radiators, desired radiation patterns can be sculpted. Dynamic metamaterial antennas hold promise for improved cost, size, weight, and power compared to conventional counterparts.
Objectives: We develop analytical methods to analyze and design reconfigurable metamaterial antennas for radar and remote sensing, wireless communication, and wireless power transfer.
Reconfigurable Intelligence Surfaces
Background: Reconfigurable intelligent surfaces can redirect incident signals toward prescribed directions. As a result, the propagating environment of wireless communication systems, which has always been deemed out of touch, becomes a design knob. This paradigm shift has sparked a whole new approach to engineering wireless radio environment and is sometimes referred to as smart radio environment.
Objectives: In a project supported by NSF and in collaboration with Duke University and Virginia Tech University, we are designing RISs that mitigate interference and allow for seamless coexistence of multiple systems.
Smart On-chip Electromagnetic Environment
Background: Conventional wired interconnects used for intra- and inter chip communication cannot scale up with the ever-growing processing demand. Their limited data rate are predicted to create a bottleneck for future processing systems. Wireless networks on chip (WNoC) are pursued as a possible solution for on-chip data transfer to augment wired interconnects to overcome their limitations. However, the on-chip propagation environment exhibits multiple scattering which can reduce data rate in WNoC systems.
Objectives: In a collaborative effort, we are designing reconfigurable intelligent surfaces that can mitigate the impact of multiple scattering and tailor the impulse response of WNoC systems in order to improve their data rate.
Computational Microwave Imaging
Background: The traditional wisdom in developing microwave sensors and imagers is to form a one-to-one relationship between the probed point and the sensed data. As the frequency of operation and the size of microwave imaging and sensor systems increases (to satisfy the desire for higher resolution), the cost and complexity of the traditional systems have also grown. In computational microwave imaging, the isomorphism between the imaging domain and the hardware sensing layer are removed, and instead, computational post-processing is used to retrieve the desired image. In fact, if the raw data collected in this manner is directly reconstructed, it may look like meaningless speckle patterns. By processing this data through computational techniques, the desired image of the scene is formed. In this framework, the data collection is faster, and the hardware are simpler and more affordable.
Objectives: We design novel computational microwave imaging for nondestructive evaluation of different structures and through wall imaging systems.