module and diode noise power spectrum and correlations
DESCRIPTION
Module and Diode Noise Power Spectrum and Correlations. Cuts Data from W-band CES #3 Run ID# 3010 B-glitch correction using adc_anomaly_info.txt -w91-multi-v3.txt (default diode rms = 0.2 counts) Not looking at TT modules (modules 85-90) Removed bad modules: 7, 8, 28, 42, 81 - PowerPoint PPT PresentationTRANSCRIPT
Module and DiodeNoise Power Spectrum
and Correlations
Cuts
Data from W-band CES #3 Run ID# 3010
B-glitch correction using adc_anomaly_info.txt-w91-multi-v3.txt(default diode rms = 0.2 counts)
Not looking at TT modules (modules 85-90)
Removed bad modules:
7, 8, 28, 42, 81
Removed bad diodes:
module 4 U2module 38 Q1Module 40 Q1
FFT of Double Demodulated Diode Signals
mV2/Hz versus freq(Hz)
Averaged over all Modules and Diodes
Scan Synchronous Signal
Other glitches
TT-modules
FFT of Double Demodulated Diode Signals
mV2/Hz versus freq(Hz)
Some Modules show Stronger Glitch Signals(could be ground pickup)
Scan Synchronous Signal
Other glitches
Q1 Q2
U1 U2
Typical Fit Result to function P1/f + P2 Typically cannot fit the first bin
Definition of White Noise Correlation (from I. Buder)
F are the frequency components from the FFT
F-bar denote complex conjugate of F
i,j are diode indices (Q1, Q2, U1, U2)
< > refer to average over all frequencies > 10 Hz
DDmod Ideal Combination Correlation Coeff
Q1 – Q2 0
U1 – U2 0
Q – U 0.5
From: Chicago Memo on Noise Correlations
Assuming NO polarization at input
Q1-Q2, U1-U2, and Q-U correlation dependence on power difference between Leg A and Leg B
Q1 - Q2U1 - U2
Q – U
Correlation Dependence on Power Imbalance, and Hybrid Imperfection
Typical Diode-Diode Noise Correlation versus FrequencyCij versus freq (Hz)
Bad Diode-Diode Noise Correlation versus Frequency from module 9Cij versus freq (Hz)
Noise Correlation Between Diodes (within same module)
* I haven’t checked, but this result seems to agree with study by I. Buder
What next ?
Implement B-glitching correction (done)
Analyze 91 modules from one CES (done)
Write fitter to fit for 1/f knee and white noise level (done)
Write fitter to fit for correlation coefficients (done)
Analyze more CES
Examine Glitch patterns in FFT (may be due SSS)