Introduction and Motivation:

Considering today’s science and industry interest to reach compact, reliable and cost-effective  
communications, systems which aim to provide such pioneering characteristics are growingly analyzed,  
designed and implemented. In this regard, microwave/millimeter wave components and antennas are  
of the common and unavoidable elements of these systems, [1]. On the other hand, the field of  
Metamaterials is still a relatively new field of study and many applications are yet to be discovered. The  
utilization of Metamaterials (MTMs) can make an important contribution to the improvement of these  
devices and many research projects are still investigating the future development in the MTM area and  
their potential fields of application. The research agenda on MTMs is now shifting towards achieving  
tunable, switchable, nonlinear and sensing functionalities. Thus, efficient MTM structures compatible  
with integrated circuits play a vital role in effective fabrication and implementation of communication  
systems, [2]. By this research, we intend to find new opportunities in the design of antennas as well as  
wireless components through the usage of conventional MTMs and also generate more applicable  
structures regarding a desired design. This fast-growing field still fascinates me and draws much of my  
research interest and effort.

Background and Literature Review:

One of the major directions of research in the field of electromagnetism has been microwave  
applications of Metamaterials structures. The structures could exhibit unique and unusual  
electromagnetic properties through which various microwave components and antennas with unique  
features have been demonstrated. So far, MTMs have been successful in many circuits and devices  
allowing phase compensating lines for Active Electronically Scanned Arrays, suppressing parasitic  
waves, nondestructive testing, Material Characterization and sensing applications, etc. Specifically, of  
the Metamaterials, the so-called negative index materials have been of interest. Although most  
demonstrations of negative index materials have been based on resonant structures, these structures  
suffer from high losses and narrow bandwidths. In this regard, the trend has recently been towards  
MTM structures which can effectively eliminate these two common drawbacks, [3]-[4].

Solution and Contribution:

We will start by a comprehensive survey of different MTM structures and their conventional  
applications. The study can be later used to predict future and potential developments. We will also  
strongly emphasize on providing a MTM unit cell with the following characteristics which provides a  
better and more efficient control on the frequency response of the unit cell:

❖Broadband and Low-Loss Volumetric Metamaterials
High performance volumetric Metamaterials have proven to overcome the bandwidth and loss  
limitations of conventional designs.
❖Transmission-Line Based Metamaterials with Arbitrary Material Tensors
These novel transmission-line (TL) based Metamaterials can exhibit tensor material properties and  
devices. In addition, tensor Metamaterials are TL based (traveling-wave structures) and they promise  
broad bandwidths of operation and low losses. These tensor TL Metamaterials allow unprecedented  
control of electromagnetic fields along a surface / radiating aperture.
❖Tunable Metamaterials
This research will incorporate tunable elements into the Metamaterials unit cell to achieve a  
controllable electromagnetic response.
We will emphasize on providing a specifically-designed MTM unit cell (e.g. embedded SRRs can be  
applicable to most devices where a control of the constitutive parameters could significantly improve  
the overall performance besides tenability and miniaturization enhancements. Previous studies have  
been performed and further studies are still welcome, [5-10]. This unit cell will be a very engineerable  
design enhancing the performance of various antennas as well as microwave/millimeter wave  
components in miniaturized overall dimensions. Analytical modeling of candidate structures besides  
software simulations and experiments will also be a major focus of this effort.


References:

[1]. K. Chang, Editor, Handbook of RF/Microwave Components and Engineering, J. Wiley & Sons, Inc
[2]. C. Caloz and T. Itoh, “Electromagnetic Metamaterials: Transmission Line Theory and Microwave  
Applications”, New York, NY, USA. Wiley, 2005.
[3]. S.M. Rudolph and A. Grbic,” A broadband three-dimensionally isotropic negative-refractive-index  
medium,” IEEE Trans. Antennas. 2012.
[4] G. Gok and A. Grbic “A printed beam-shifting slab designed using tensor transmission-line  
metamaterials, ” IEEE Trans. Antennas. Propag. 2013.
[5] F. Farzami; S. Khaledian; B. Smida; D. Erricolo, “Pattern Reconfigurable Printed Dipole Antenna  
Using Loaded Parasitic Elements,“IEEE Antenn. Wireless Propag. Lett. 2016.
[6]. Farzami, F.; Norooziarab, M., “Experimental Realization of Tunable Transmission Lines Based on  
Single-Layer SIWs Loaded by Embedded SRRs,”  IEEE Trans. Microw. Theory Tech. 2013.
[7]. Norooziarab, M.; Rafaei-Booket, M.; Atlasbaf, Z.; Farzami, F., “A tunable transmission line based  
on an SIW loaded by a new single-cell metamaterial,”  Telecommunications (IST), 2012 Sixth  
International Symposium on , vol., no., pp.75,79, 6-8 Nov. 2012.
[8]. F. Farzami, K. Forooraghi, and M. Norooziarab, “Miniaturization of a microstrip antenna using a  
compact and thin magneto-dielectric sub-strate,” IEEE Antenn. Wireless Propag. Lett. 2011.
[9]. Farzami, F.; Forooraghi, K.; Norooziarab, M., “Design and Modeling of a Miniaturized Substrate  
Integrated Waveguide Using Embedded SRRs,”  IEEE Antenn. Wireless Propag. Lett. 2011.
[10]. Majid Norooziarab, Zahra Atlasbaf, Farhad Farzami, “Substrate integrated waveguide loaded by  
3-dimensional embedded split ring resonators,”  AEU - International Journal of Electronics and  
Communications, 2014.
Microwave Applications of Metamaterials
[6] Single-layer SIW loaded by VLESRR
[7] Single-layer SIW loaded by VLCSRR
[8] Ultra-thin magneto-dielectic substrate
[9] ESRR in multi-layer SIW
[5] VLESRR in parasitic elements
[10] Accessible ESRR in multi-layer SIW

Farhad Farzami