We are pleased to announce the first session in our student seminar series. Two of our students will be presenting on  Wednesday, March 9 from 3:00 pm – 4:00 pm in NREF 1-003. 

Seminar #1: Parinaz Naseri – “Dual-Band Circularly-Polarized Transmit-Array Unit-Cell at X and K Bands”

Abstract

This work presents a novel design and analysis on a dual-band circularly-polarized transmit-array unit-cell based on miniaturized elements. The proposed structure is a two dimensionally anisotropic structure composed of capacitive patches, inductive split rings, and an inductive grid. The structure is designed to respond differently to each orthogonal component of a circular polarized wave illuminating the transmit-array and transmits a circularly polarized plane wave. The proposed structure operates at 10.8 GHz and 16.7 GHz with transmission coefficients above -1 dB at both. The simulated and measured results of the unit-cell prototype agree well.

Biography

Parinaz is a master student at University of Alberta in Electrical Engineering- Microwaves. She recieved her Bachelor of Science degree in Electrical Engineering- Telecommunications at University of Tehran in 2013. Her research interest is in circularly polarized transmit-arrays and meta-surfaces with satellite communication application.

Seminar #2: Hossein Saghlatoon – “RFID: Challenges and Advances“

Abstract

Radio-frequency identification (RFID) technology provides compelling means for the automatic identification and tracking of items. This is achieved by labeling them with battery-free remotely addressable electronic tags composed of an antenna and an integrated circuit (IC). The use of propagating electromagnetic waves at ultra-high frequencies (UHF) for powering and communicating with the passive tags enables rapid interrogation of a large quantity of tags through various media from the distances of several meters. In comparison to bar-codes, RFID tags allow the data stored in them to be updated wirelessly at any time. A special feature in the design of antennas for RFID tags is that they need to be interfaced directly to an ultra-low-power RFID application specific integrated circuit (tag IC). The impedance of a tag IC is largely determined by the charge pump in the chip frontend. It is a non-linear device and makes the IC impedance capacitive (example of a typical value: 15−j150 Ω). Therefore, the design of complex conjugate impedance matching for tag antennas is fundamentally different compared with conventional antennas which are commonly matched to 50 Ω. Perhaps the greatest challenge yet to be overcome in the design of tag antennas is the undesired antenna-matter interaction, as in practice RFID tags are mounted on platforms with unspecified material properties. This is a particularly pronounced issue when tags are mounted on conductive items. The requirement of low-profile antenna structure leads to a situation where the separation of the antenna from a conductive surface is much less than a quarter wavelength. Hence, the antenna current flows predominantly horizontal to a conductive surface. In this configuration, the antenna operation is strongly influenced by the conductor. Indeed, if the proximity of a conductive body is omitted in the design, the tag is likely not functional at all when mounted on a conductive item.

In this session, a miniaturized UHF RFID tag developed for industrial harsh environment applications like oil and gas industries is presented. The tag is designed based on an open-ended slot structure and fed by a primary radiator from the middle. Feeding the antenna using coupling mechanism by a primary radiator, results to lower fabrication complexity and costs as well as mechanical durability against continuous vibrations, humidity, water and mud. The whole tag is 0.084λ×0.066λ and can be read up to 5 m in the US band and 3 m in the EU band.

Biography

Mr. Hossein Saghlatoon is a Ph.D. student in the Department of Mechanical Engineering at the University of Alberta. He received his B.Sc. in Electrical Engineering from Ferdowsi University of Mashhad , Iran (2012) and his M.Sc. in RF Electronics from the Department of Electronics and Communications Engineering, Tampere University of Technology, Finland (2014). His research interests include Inkjet Printing and 3D printing of RF/Microwave circuits, Radio Frequency Identification Technology and sensing antennas. He is currently working on realization of sensor RFID tags utilizing 3D printing Technology.

Free pizza and refreshments will be served.