Doctoral Dissertations

Keywords and Phrases

Antenna; Interference; Minimum scattering antennas; Mutual coupling; Radio frequency identification; Vector differential backscattering


"Passive Radio Frequency Identification (RFID) is a short range technology for transferring information. The main advantage of passive RFID systems over active communication systems is the battery-less operation at the client sides. However, there are two major challenges that limit the widespread adaptation of passive RFID systems: short communication range and low read rate in dense deployments. This dissertation addresses these issues by studying the root causes and develops solutions for them.

In this dissertation, understanding the backscattering behavior of antennas and also the mutual coupling interactions among them are found to be the root causes of the two above-mentioned challenges for RFID networks. Thus, by studying these two main root causes solutions for them are proposed, investigated and verified, by simulations and measurements. The contributions in this dissertation include: (1) Design of a new measurement technique to estimate the structural scattering coefficient of a linear antenna. (2) Showing that the well-known Green model cannot completely explain the variation of the radar cross section of a T-match bowtie antenna over its Г plane. (3) Introducing dual loading in designing RFID antenna tags to: (a) Increase the vector differential backscattering signal, (b) Produce higher order modulations. (4) Introducing a new state for RFID tags in that tags switch to a low scattering states to: (a) suppress their interference to a target antenna in the network. (b) Stabilize the RCS of the target antenna. (c) Increase read rate in RFID networks. (5) Numeric analysis of the mutual coupling impedance for two side by side scattering antennas. (6) Introducing a multi-port RFID which can switch to different load impedances to help a target antenna in its vicinity increase its signal over the level when the target is alone in the field"--Abstract, page iv.


Zawodniok, Maciej Jan, 1975-

Committee Member(s)

Ghasr, Mohammad Tayeb Ahmad, 1980-
Zoughi, R.
Pommerenke, David
Chellappan, Sriram


Electrical and Computer Engineering

Degree Name

Ph. D. in Electrical Engineering


Missouri University of Science and Technology

Publication Date

Summer 2016

Journal article titles appearing in thesis/dissertation

  • Measuring the structural scattering coefficient of a linear RFID antenna using minimum variance unbiased estimator
  • Dual loaded RFID tag for higher order modulations
  • Application of low scattering antennas to RFID networks
  • A solution to low read rate problem in RFID scattering networks
  • Preliminary study on mutual coupling effect on a passive RFID antenna array
  • Cooperative interference control in neighboring passive antennas with application to RFID networks


xiv, 170 pages

Note about bibliography

Includes bibliographic references.


© 2016 Shadi Ebrahimi-Asl, All rights reserved.

Document Type

Dissertation - Open Access

File Type




Thesis Number

T 11479

Electronic OCLC #