Masters Theses


Chunyu Wu

Keywords and Phrases

IC Immunity; Near Field Scan; Radio Frequency Interference; RFI Rectification; SMPS


"This thesis discusses two parts.

In the first part, the rectification behavior of popular instrumentation amplifiers is measured in both common mode and single-ended RF noise injection. It is recommended that AD8221 be used in common mode RF noise injection environment. And AD8220 and AD8429 are recommended in single-ended RF noise injection environment. The mechanism of RF noise rectification inside in-amps is also discussed. It is verified that rectification mainly happens at the non-inverting input of two op-amps in the first stage of an in-amp. The DC voltage difference between inverting input and non-inverting input of the in-amp is further amplified, which will cause a large DC offset at the output. It is shown that symmetry of the first stage in an instrumentation amplifier is very important. The asymmetry of the first stage will increase the DC offset at the output dramatically. The layout of gain resistor should be symmetric to reduce DC offset at the output.

In the second part, the near field coupling from SMPS circuits to a nearby antenna is studied using dipole moments. The dipole moments are extracted from scanned H fields on a plane above SMPS circuits, and then imported into an HFSS model to do full wave simulation. The simulated coupling matches well with direct measurement. Methods to resolve magnitude and phase of near fields of SMPS noise source are also introduced"--Abstract, page iii.


Fan, Jun, 1971-

Committee Member(s)

Pommerenke, David
Khilkevich, Victor


Electrical and Computer Engineering

Degree Name

M.S. in Electrical Engineering


Missouri University of Science and Technology

Publication Date

Spring 2017


viii, 28 pages

Note about bibliography

Includes bibliographical references (page 27).


© 2017 Chunyu Wu

Document Type

Thesis - Open Access

File Type




Thesis Number

T 11128

Electronic OCLC #