Masters Theses


Pratim Shah


"Passive UHF RFID tags works on the principle of backscattering mechanism. In realistic environment, there are multiple objects and tags that create complex, multipath propagation scenarios with numerous null-points, reduced read range and read rate.

In general, the RF frontend of tags could be controlled such that the negative effects of multipath propagation are reduced or even inverted thus implementing a virtual beamforming. The theoretical framework of beamforming in RFID system, using additional tags as virtual antenna arrays, has been discussed before. The presented study evaluates the feasibility of such beamforming in passive RFID systems. Moreover, it synthesizes an appropriate propagation model that explains the experimental results and will aid in refining the beamforming scheme. Number of practical experiments has been carried out to validate the propagation models that were employed during the scheme design phase. The experimental results are presented and discussed.

Although above method achieved increase in signal strength at certain locations, it had negative effect at remaining locations. Thus, a more dynamic beamforming would be required to achieve consistent increase in signal strength at all locations. Hence, above beamforming method is further extended to achieve dynamic beamforming. Method of dynamic beamforming is simulated and its results are discussed. Also, aspects of designing RF tag for achieving dynamic beamforming has been discussed"--Abstract, page iv.


Zawodniok, Maciej Jan, 1975-

Committee Member(s)

Kosbar, Kurt Louis
Shi, Yiyu


Electrical and Computer Engineering

Degree Name

M.S. in Electrical Engineering


Missouri University of Science and Technology

Publication Date


Journal article titles appearing in thesis/dissertation

  • Experimental feasibility study of a passive RFID-based distributed beamforming framework
  • RF tag design for achieving dynamic beamforming in RFID


ix, 67 pages

Note about bibliography

Includes bibliographical references.


© 2012 Pratim Mukesh Shah, All rights reserved.

Document Type

Thesis - Open Access

File Type




Subject Headings

Radio frequency identification systems -- Design
Beam optics
Radar transmitters

Thesis Number

T 10648

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