پنجمین کنفرانس فناوری موج میلیمتری و تراهرتز

To achieve the dramatic improvements in capacity and spectral efficiency needed for fifth generation (5G) systems to accommodate the ever increasing number of users who require ubiquitous access to high volumes of wireless data, two technological directions have independently emerged: 1) massive MIMO - base stations equipped with a very large number of antennas (100 or more) that can simultaneously accommodate many co-channel users 2) Millimeter wave (mm-wave) communications around and above 30 GHz where the spectrum is less crowded and greater bandwidths are available. The combination of millimeter-wave and massive MIMO has the potential to dramatically improve wireless access and throughput. This workshop outlines the benefits, challenges, and potential solutions associated with communication systems that incorporate these technologies.

This work shop is divided three parts:

• The metamaterial structures, fundamental and concepts:
  In this part, a review will be done on the fundamental of metamaterial structures, applications and advantages.
• The useful structure for millimeter wave applications:
  The substrate integrated waveguides and air gap waveguide are two new structures which can be used in design of the millimeter wave circuits and systems.
  In this workshop, the fundamental of substrate integrated waveguide structure and new type of this structure such as slow wave SIW, half mode SIW, air filled SIW, and metamaterial structures based on SIW would be presented.
• Active metamaterial structures:
  In this part, application of the metamaterial transmission line in the active transmission lines would be discussed.

Graphene plasmon has attracted great attention as a viable tool for fast electrical manipulation of light. The prospects for applications to electro-optical modulation, optical sensing, quantum plasmonics, and light harvesting are further stimulated by the relatively low level of losses and high degree of spatial confinement that characterize these excitations compared with conventional plasmonic materials, alongside the large nonlinear response of graphene. In this workshop, first, graphene properties, when it is interacting with electromagnetic waves, are considered. Then, the plasmonic guided mode of infinite graphene sheet and its characteristics is introduced. I also present various graphene-based waveguides. The next section in this workshop is devoted to the study of localized plasmonic modes on graphene ribbons and discs. Finally, applications of graphene plasmonics and graphene-based optical devices will be discussed.

Inventing an indivisibility cloak to make things disappear has been always a dream for human being throughout the history. Recently, by development of metamaterials, materials with extraordinary electromagnetic properties not existing in nature, it seems that the old dream is going to come true.
Natural materials owe their electromagnetic properties to atoms, and molecules from which they are composed of. On the other hand, metamaterials are engineered structures in which inclusions much smaller than the operation wavelength replace the role of the atoms and molecules of a conventional material in defining electromagnetic properties. Metamaterials can be designed to achieve desirable electromagnetic properties at desired frequency ranges, which provides additional flexibility in the design of microwave, and optical devices.
In this workshop, first Metamaterials are introduced and the methods used to design, analyze, and fabricate them are discussed. Then, we will learn how to use Metamaterials to make things disappear! In this regard, the transformation optics theory is introduced and discussed. Then different invisibility cloaks developed so far, are discussed and compared to each other, and the advantages, and disadvantages each method provides are investigated. After that, the cloaking structures developed, and fabricated in the “nano-photonics and metamaterials research group of University of Tehran”, and their experimental results are demonstrated. Finally, we will explore the potential future directions of the field.

In this workshop, principles of mmwave measurement together with methods and challenges are discussed. Based on the scheduled time, the followings matters are propounded:

• Cable and connectors
• Permittivity measurement
• Antenna measurement
• Scattering parameter test