1. Beam Secondary Shower Acquisition System: Cables Measurements Student Meeting Jose Luis Sirvent PhD. Student 22/07/2013

2. 1. Cable measurements campaign. 1 st Experiment layout: – Frequency Response (Bode Plot ‘Magnitude’) – Phase displacement (Bode Plot ‘Angle’) LeCroy Scope Adapters BNC-N BNC Ch1 50 ohm Splitter N-2xBNC 50 ohm Loop (double Female) N-Connector 10 ns 8 ns Func. Generator BNC Ch2 50 ohm CK50 2 x 88 m = 176m

3. 1. Cable measurements campaign. 1 st Experiment : – Frequency Response (Bode Plot ‘Magnitude’) Measuring the ratio V2rms/V1rms at different frequencies

4. 1. Cable measurements campaign. Very good agreement Pspice model: Fits well with 176m!! Analitical functions: Where : C(l), L(l) and Rac(l,f), Gac(l,f) Values of Rac and Gac have been calculated from: http://issues.cern.ch/browse/BIWS-422

5. 1. Cable measurements campaign. 2 nd Experiment layout: – Pulse distortion (Integrator effect) – Step response (Low-pass filter) LeCroy Scope Adapters SMA-N SMA-BNC Ch1 50 ohm Splitter SMA-2xSMA 50 ohm Loop (double Female) N-Connector 4 ns 8 ns Pulse Generator SMA-BNC Ch2 50 ohm CK50 2 x 125 m

6. 1. Cable measurements campaign. 2 nd Experiment (lab testing): Equipment works well, only delay of 8ns 4 ns 8 ns CK 50 Cable Connection -PicoSecond 2600C: Pulse generator  1 - 100ns Selectionable delay Repetition Rate  1-100KHz Vo  45V (-70dB) Zo  50 ohm -LeCroy Scope: Sampling Freq  5Gsps Scale  2ns/div Zin  50 ohm -Testing pulses characteristics: Rise time  419ps Fall time  837ps Pulse width  700ps System delay  8ns

7. 1. Cable measurements campaign. 2 nd Experiment (Pulse distortion with Square pulse): Square pulse ~4ns: Rise: 407ps  596ps Falling: 876ps  3.436ns Width: 2.464ns  3.298ns Whole Pulse: 3.747ns  7.330ns (Δ195%) Attenuation: 3V  1.75V (-4.68dB) *Yellow: Input *Pink: Output

8. 1. Cable measurements campaign. 2 nd Experiment (Pulse distortion with ~1.5ns pulse): Square pulse ~1.5ns: Rise: 378ps  606ps Falling: 860ps  4.375ns Width: 763ns  1.369ns Whole Pulse: 2.001ns  6.350ns (Δ317%) Attenuation: 2.75V  1V (-8.7dB) *Yellow: Input *Pink: Output Beware the long tails!! 25ns

9. 1. Cable measurements campaign. 2 nd Experiment (Step Response & System Identification): Matlab System Identification Toolbox Arxqs model fits 94.64%!! Delay = 759ns – 8ns (probe) = 751ns

10. 1. Cable measurements campaign. Comparison of the Matlab model TF(f)

11. 1. Cable measurements campaign. Comparison of the Matlab model TF(f) Matlab model (arxqs) Pspice model (Tlossy)

12. 1. Cable measurements campaign. 3 rd Experiment layout: – A) Cable noise measurement (Noise normal distribution & Noise Frequency Spectrum) Usage of 2 sets of data at different sampling frequency: 500Mhz & 5Ghz LeCroy Scope Adapter BNC-N BNC Ch1 50 ohm Loop (double Female) N-Connector 10 ns BNC Ch2 50 ohm Load 50 ohm CK50 2 x 88 m = 176m

13. 1. Cable measurements campaign. A) Cable noise measurement (Noise Frequency Spectrum Fs= 500Mhz) Set 1: 10 Segments of 5ms recorded at 500Mhz with only scope loaded Set 2: 10 Segments of 5ms recorded at 500Mhz with cable loaded Extraction of FFT 1 – 250Mhz for each segment measured in set 1 and averages of FFT Extraction of FFT 1 – 250Mhz for each segment measured in set 2 and averages of FFT FM Radio Stations & TV AM Radio Stations & Others A B

14. 1. Cable measurements campaign. A) Cable noise measurement (Noise Frequency Spectrum Fs= 5Ghz) Set 1: 10 Segments of 500us recorded at 5Ghz with only scope loaded Set 2: 10 Segments of 500us recorded at 5Ghz with cable loaded Extraction of FFT 1 – 2.5Ghz for each segment measured in set 1 and averages of FFT Extraction of FFT 1 – 2.5Ghz for each segment measured in set 2 and averages of FFT TV StationsGSM-900 GSM-1800 WI-FI C D

15. 1. Cable measurements campaign. A) Cable noise measurement (Noise Frequency Spectrum Fs= 500Mhz & 5Ghz ) A look in detail (Most important contribution 330KHz!!) 300KHz 1.67GHz 750MHz 167MHz A B C D

16. 1. Cable measurements campaign. A) Cable noise measurement (Noise Frequency Spectrum Fs= 500Mhz & 5Ghz ) A look in semi-logaritmic scale (Easier to see that the most important contribution is at 330KHz!!)

17. 1. Cable measurements campaign. A) Cable noise measurement (Noise Frequency Spectrum Fs= 500Mhz) 1.23Khz 19.6Khz 330Khz

18. 1. Cable measurements campaign. A) Cable noise measurement (Amplitude distribution at Fs= 500Mhz)

19. 1. Cable measurements campaign. A) Cable noise measurement (Amplitude distribution at Fs= 5Ghz)