Doctoral Dissertations

Keywords and Phrases

EMI; Near field scanning; Near to far field; Source localization


"For complex and large systems with multiple sources, it is often difficult to localize the sources of radiation. Near-field electromagnetic scanning is used often for root-cause diagnosis by determining field distribution close to the PCB. In the near-field, the evanescent waves are dominant, which may lead to the misinterpretation of them being the dominant sources contributing to the far-field. Another limitation of near-field scanning is that the probe may not be able to access all locations near the PCB due to the complex geometry and high component density. Two-dimensional synthetic aperture radar is a well-known technique used for antenna diagnostic and alignment of phase array antennas. Using a technique which is derived from the synthetic aperture radar we present emission source microscopy to localize the sources of active radiation on a PCB. After obtaining the location of sources, using near field to far-field transformation, it is shown that the far-field radiation patterns and the total radiated power can be estimated. Using masking algorithms the contribution of individual sources to far-field can be determined. The source localization methodology is presented along with simulation and measurement results on real-DUTs. The results show that the proposed method is capable of detecting multiple active sources on a complex PCB. Different phase measurement methods are presented along with the measurement results. Also, methods to reduce the scanning time for source localization are presented"--Abstract, page iii.


Sedigh, Sahra
Pommerenke, David

Committee Member(s)

Khilkevich, Victor
Zoughi, R.
Liu, Xiaoqing Frank


Electrical and Computer Engineering

Degree Name

Ph. D. in Computer Engineering


Missouri University of Science and Technology

Publication Date

Summer 2014


xiii, 131 pages

Note about bibliography

Includes bibliographical references (pages 126-130).


© 2014 Pratik Rajesh Maheshwari, All rights reserved.

Document Type

Dissertation - Open Access

File Type




Subject Headings

Electromagnetic interference
Near-fields -- Measurement
Field emission
Synthetic aperture radar

Thesis Number

T 10535

Electronic OCLC #