6. Design of Reconfigurable Intelligent Surfaces and Metasurfaces using Generative Artificial Intelligence 

This research utilizes Generative Artificial Intelligence (AI), particularly Conditional Variational Autoencoders (CVAEs), for the design and optimization of metasurfaces. CVAEs are employed to explore the complex design space by learning efficient latent representations of metasurface configurations and generating new designs with desired electromagnetic properties. This AI-driven approach aims to automate the design process, improve exploration of potential configurations, and enhance the performance of RIS and metasurfaces, enabling advanced applications in wireless communications, sensing, and imaging technologies.

5. Design of a Reconfigurable Intelligent Surface for 6G Communications

Massive multiple-input multiple-output (MIMO) technology is at the core of 5G cellular communication technology. The base stations make use of arrays of 64 or more antenna-integrated radios to enable precise beamforming towards any location in the cell and to enable spatial multiplexing of many user terminals. The technology can focus energy in space, but it cannot overcome major weaknesses imposed by the propagation environment, such as shadow fading. Reconfigurable intelligent surfaces (RIS) are one of the promising candidates for upcoming 6G communications. It consists of a large number of tunable unit cells to manipulate electromagnetic waves. By programming the unit cells of the RIS, the reflected signal can be focused in the desired direction. Hence, it is possible to improve the performance of wireless communications using RIS.

4. Digitally Reconfigurable Transmitarry with Beam Steering and Polarization Conversion Properties (6G Communications or Radars Applications)

Recently, with the advance of coding meta-surface and digital meta-surface, there has been a great interest in developing digitally coded surfaces for beam steering and polarization conversion among the antenna community. To steer the beam in different directions and get polarization-converted waves, conventional phase array antennas are being used. The phase shifters used in conventional phased array antennas have a high insertion loss. Generally, a power amplifier is used to enhance the signal strength of conventional phased array antennas. Low insertion loss, lightweight, low-prole, and low-cost antennas with beam steering and polarization conversion operation are required for 6G communications, radar, and satellite communication applications. Conventional phased array antennas are being used for such applications, which are bulky, expensive, and analog. Transmitarray is one of the promising candidates that can replace conventional phased array antennas for beam scanning and polarization conversion operations.

3. Implantable Antennas for Brain-Machine Interface 

The recently developed brain-machine interface (BMI) is an emerging and promising area that is expected to restore functionalities to paralyzed individuals. Research on the BMI has received extensive attention since the first experiment verified that electrical activity generated by ensembles of cortical neurons can be employed directly to control a robotic manipulator. The BMI consists of several parts: sensors for neural recording, a signal processing IC, a program for brain simulations, a wireless link to connect with an external unit, and real-time brain mapping to effectively track and decode the neural activities. Reliable BMI systems are still in the development stage. Neural recording systems need to be very miniaturized, biocompatible, wirelessly powered, and able to flow data directionally. It is the most promising and demanding task to extract the brain signal data from the implanted systems.

2. Electromagnetic Measurement 

With the growing interest in personalized medical devices, research on Brain Implantable Medical Devices (BIMDs) is emerging. These BIMDs essentially include an RF technology with integrated antennas to create wireless links. Unlike in free-space condition, antennas of BIMDs propagate through human tissues. Therefore, the BIMDs should be measured and verified under the same condition as the actual human brain. The permittivity and loss tangent measurement of  different tissue equivalent materials are very import work.

1. Microwave Imagining Systems (Low Loss Antenna Design) for Brain Injury Diagnosis

Brain injury is a significant cause of disability and mortality worldwide, resulting from various traumatic and non-traumatic events such as accidents, strokes, drug abuse, tumors, infections, and other diseases. Given the rapid deterioration associated with brain injuries, prompt diagnosis and management are crucial for effective treatment and recovery. Fast and accurate on-the-spot detection using head imaging plays a vital role in providing timely medical intervention to enhance the chances of a full recovery. In this research, a dielectric resonator-based antenna array is designed specifically for microwave imaging applications aimed at detecting brain injuries. The characteristics of the array make it suitable for high-resolution imaging, offering a non-invasive and efficient approach for early detection and diagnosis of brain trauma, potentially improving patient outcomes through timely medical response.