TY - JOUR
T1 - SNR Analysis and Optimization in Near-Field Scanning and EMI Applications
AU - Maghlakelidze, Giorgi
AU - Yan, Xin
AU - Guan, Li
AU - Marathe, Shubhankar
AU - Huang, Qiaolei
AU - Bae, Bumhee
AU - Hwang, Chulsoon
AU - Khilkevich, Victor
AU - Fan, Jun
AU - Pommerenke, David
PY - 2018/8/1
Y1 - 2018/8/1
N2 - In a near-field scanning system, each element of the measurement chain contributes to the thermal noise power density: probe, cables, amplifiers, and the measuring instrument. The signal-to-noise ratio (SNR) is strongly affected by the source output impedance, source temperature, the lossy transmission lines between probe and amplifiers, amplifier noise, amplifier temperature, and amplifier gain. By minimizing the loss between the probe and by using ultralow-noise amplifiers (noise figure (NF) < 0.5 dB), SNR improves by >10 dB, compared to a setup using a 1-m cable and a 3-dB NF amplifier. A resonant probe that is cooled with liquid nitrogen improves measurement SNR by an additional 10-12 dB, as compared to a broadband probe of similar loop size. To combine the advantages of a resonant probe, without sacrificing the ability to measure broadband, a proof of concept is demonstrated that uses a tunable resonant probe which is synchronized to the frequency sweep of the spectrum analyzer.
AB - In a near-field scanning system, each element of the measurement chain contributes to the thermal noise power density: probe, cables, amplifiers, and the measuring instrument. The signal-to-noise ratio (SNR) is strongly affected by the source output impedance, source temperature, the lossy transmission lines between probe and amplifiers, amplifier noise, amplifier temperature, and amplifier gain. By minimizing the loss between the probe and by using ultralow-noise amplifiers (noise figure (NF) < 0.5 dB), SNR improves by >10 dB, compared to a setup using a 1-m cable and a 3-dB NF amplifier. A resonant probe that is cooled with liquid nitrogen improves measurement SNR by an additional 10-12 dB, as compared to a broadband probe of similar loop size. To combine the advantages of a resonant probe, without sacrificing the ability to measure broadband, a proof of concept is demonstrated that uses a tunable resonant probe which is synchronized to the frequency sweep of the spectrum analyzer.
KW - Electromagnetic interference (EMI)
KW - field sensors and probes
KW - GPS
KW - GSM
KW - liquid nitrogen
KW - measurement uncertainty
KW - near-field modeling and measurements
KW - probe cooling
KW - resonant probes
KW - signal-to-noise ratio (SNR)
KW - Wi-Fi
UR - http://www.scopus.com/inward/record.url?scp=85041391892&partnerID=8YFLogxK
U2 - 10.1109/TEMC.2018.2792778
DO - 10.1109/TEMC.2018.2792778
M3 - Article
AN - SCOPUS:85041391892
SN - 0018-9375
VL - 60
SP - 1087
EP - 1094
JO - IEEE Transactions on Electromagnetic Compatibility
JF - IEEE Transactions on Electromagnetic Compatibility
IS - 4
ER -