School of
Information Technology and Electrical Engineering

Speaker: Reza Dehbashi
Seminar Date: Fri, 27/10/2017 - 11:00
Venue: 49-502; AEB Seminar Room
Host: Prof Amin Abbosh

Seminar Type:  PhD Confirmation Seminar


Transformation Optics (TO) and metamaterials are used to manipulate electromagnetic waves and thus improve electromagnetic-based imaging systems by designing novel devices or by introducing new concepts. For the first time, we discuss uniqueness of solutions for Maxwell’s equations and uniqueness of inverse scattering for TO-based structures. Invisibility cloaks are proposed to hide interfering prosthetic materials in the body in the imaging. Sensor-invisibility cloaks are also designed for near-field imaging to prevent the sensors to interfere with the transmitted/reflected signals. The, novel flat lenses are introduced and a method is proposed toincrease numerical aperture of the proposed flat lenses. The method can also be used to increase the numerical aperture of the cells in field cameras. The pattern of antennas is shaped to be flat at certain angles to have uniform field illuminators for medical applications. Using novel transformation functions, new sets of hyper-lenses are proposed to direct the waves in the desired direction or focus in a particular point. A new concept is proposed to reduce the size of electromagnetic devices. Size reduction is beneficial in medical imaging. It allows more sensors to be added to the system for improved imaging resolution. Moreover, it makes them more portable. New antennas are proposed to be smaller, have better gain, have lower side lobe levels or in an array form; they remove the grating lobe by using novel loaded antennas with novel metamaterial unit cells. Also, new electromagnetic wave absorbers are designed to absorb undesired radiated fields in the clinical environment or around the imaging systems. They can also be used between the antennas to reduce mutual coupling that might otherwise adversely affect the accuracy of detection. They would be smaller, conformal, and transparent, or have higher absorption rate. This target can be achieved by using new metamaterials unit cells and using cells with new shape and new materials.


Reza Dehbashi is currently researching at Microwave Group with the School of Information Technology and Electrical Engineering, University of Queensland, Australia. He has been the first author of tens of papers on novel/enhanced antennas and microwave systems, negative refraction of electron waves in Graphene, electromagnetic wave manipulation using Transformation Optics, cloaking of electromagnetic waves (invisibility cloaks), physics and modelling of metamaterials and metasurfaces, near-zero materials and their applications, Finite Difference Time Domain (FDTD) and Conformal Finite Difference Time Domain (CFDTD) numerical schemes, applied electromagnetics, electromagnetic theory and electromagnetic imaging systems.