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Sergio Mariotti s.mariotti@ira.inaf.it Göteborg, jun 19 th 2006

Reduction of the Uncertainty on Noise Figure Measurements A. Cremonini 1 , M. De Dominicis 2 , S. Mariotti 1 , E. Limiti 3 , A.Serino 3. INSTITUTE OF RADIOASTRONOMY, - ITALY. UNIVERSITY “TOR VERGATA” - ROME. 1 INAF – Institute of Radioastronomy - Bologna – Italy

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Sergio Mariotti s.mariotti@ira.inaf.it Göteborg, jun 19 th 2006

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  1. Reduction of the Uncertainty on Noise Figure Measurements A. Cremonini 1, M. De Dominicis 2, S. Mariotti 1 , E. Limiti 3, A.Serino 3 INSTITUTE OF RADIOASTRONOMY, - ITALY UNIVERSITY “TOR VERGATA” - ROME 1INAF – Institute of Radioastronomy- Bologna – Italy 2Elettronica s.p.a. – V. Tiburtina Valeria, Rome – Italy 3University “Tor Vergata” – Electronic Eng. Dept.– Rome - Italy Sergio Mariotti s.mariotti@ira.inaf.it Göteborg, jun 19th 2006

  2. WHY Reduce Uncertainty? INSTITUTE OF RADIOASTRONOMY, - ITALY UNIVERSITY “TOR VERGATA” - ROME +/- 3.5 % = +/- 0.15 dB For a receiver:NF = 0.3 +/-0.15 dBTe = 21 +/- 11 K Uncertainty should be much lower than the value to be measured Sergio Mariotti Göteborg, jun 19th 2006

  3. HowReduce Uncertainty? INSTITUTE OF RADIOASTRONOMY, - ITALY UNIVERSITY “TOR VERGATA” - ROME • Looking for and Find Sources of Uncertainty (U) • Minimize the sources wherever it is possible • Analyze and propagate uncertainty • Since U(ENR) is dominant, let do calibration of NoiseSource with a Secondary Standard (liq. N2) • Let Practical operations accurate as possible Sergio Mariotti Göteborg, jun 19th 2006

  4. Involved Environments INSTITUTE OF RADIOASTRONOMY, - ITALY UNIVERSITY “TOR VERGATA” - ROME Room Temperature Cryogenic /on Dewar - easier - faster - accurate - less jitter - more realistic - accurate Sergio Mariotti Göteborg, jun 19th 2006

  5. Sources (causes) of Uncertainty:Propagation, Math Formulation F12 F1 = 3 dB G1= 15 dB F2 = 10dB INSTITUTE OF RADIOASTRONOMY, - ITALY UNIVERSITY “TOR VERGATA” - ROME • Depend on many causes, even U(ENR) Depend on U(ENR) Sergio Mariotti Göteborg, jun 19th 2006

  6. Causes of Uncertainty:Graphical - Intuitive Ph Ph Ph Pc Pc Pc Te Tc Th Te Tc Th Tc Te Th INSTITUTE OF RADIOASTRONOMY, - ITALY UNIVERSITY “TOR VERGATA” - ROME Reducing Tc, will reduce U(Te) Reducing U(Th) and U(Tc) will reduce U(Te) Increasing Th don’t reduce U(Te) , because U(Th)/This a constant Instead increase Th may generate non-linearity . Yopt 2…5 Sergio Mariotti Göteborg, jun 19th 2006

  7. Causes of Uncertainty:Practical, Tips&Tricks 6 dB 10 dB INSTITUTE OF RADIOASTRONOMY, - ITALY UNIVERSITY “TOR VERGATA” - ROME |S11 ON| , |S11 OFF| < - 33 dB Selected Attenuator PT 100 A Cascade Ferrite Isolators Precision Connectors / Connector Care NO cables movement Environment: Thermostatic room, Type A Uncert. << Type B Uncert. Sergio Mariotti Göteborg, jun 19th 2006

  8. Other causes of Uncertainty: rNS rDUT INSTITUTE OF RADIOASTRONOMY, - ITALY UNIVERSITY “TOR VERGATA” - ROME Mismatch: A closed form expression doesn’t exist Approximate Expression Sergio Mariotti Göteborg, jun 19th 2006

  9. Principle of Operation 1/3 800 mW 800 mW 9400 mW 3200 mW 9400 mW 3200 mW POWER METER POWER METER POWER METER POWER METER POWER METER POWER METER Liq. N2 77 K Liq. N2 77 K Liq. N2 77 K Liq. N2 77 K Liq. N2 77 K Liq. N2 77 K INSTITUTE OF RADIOASTRONOMY, - ITALY UNIVERSITY “TOR VERGATA” - ROME Noise Source + Attenuator Sergio Mariotti Göteborg, jun 19th 2006

  10. Principle of Operation 2/3 INSTITUTE OF RADIOASTRONOMY, - ITALY UNIVERSITY “TOR VERGATA” - ROME Vector Correction Sergio Mariotti Göteborg, jun 19th 2006

  11. Pictures INSTITUTE OF RADIOASTRONOMY, - ITALY UNIVERSITY “TOR VERGATA” - ROME • Coaxial • 1-18 GHz • WR 28 • 26.5-40 GHz • WR 22 • 33-50 GHz Sergio Mariotti Göteborg, jun 19th 2006

  12. Data Analysis INSTITUTE OF RADIOASTRONOMY, - ITALY UNIVERSITY “TOR VERGATA” - ROME MatLab®codes has been used to: Process spar of non insertable Adapter Compute Mismatch and Available Gain Instruments control and automatic data collection Calculate ENR and associated Uncertainty Sergio Mariotti Göteborg, jun 19th 2006

  13. Uncertainty of the Result S par Uncertainty INSTITUTE OF RADIOASTRONOMY, - ITALY UNIVERSITY “TOR VERGATA” - ROME Depend on U(Tcryo) S par Uncertainty Uncertainty of VNA is dominant ( 0.045 dB - hp 8510C ) Sergio Mariotti Göteborg, jun 19th 2006

  14. Results andAssociated Uncertainty INSTITUTE OF RADIOASTRONOMY, - ITALY UNIVERSITY “TOR VERGATA” - ROME U(ENR) was +/- 0.15 dB U(ENR) = +/- 0.06 dB Sergio Mariotti Göteborg, jun 19th 2006

  15. Spin-off for the LNAs INSTITUTE OF RADIOASTRONOMY, - ITALY UNIVERSITY “TOR VERGATA” - ROME Sergio Mariotti Göteborg, jun 19th 2006

  16. WHAT can we do ? 1/3 INSTITUTE OF RADIOASTRONOMY, - ITALY UNIVERSITY “TOR VERGATA” - ROME • No possibility to further reduce ENR Uncertainty • … but we may transfer our expertise to reduce ENR Uncertainty of other Noise Sources • REQUEST and submit a PROPOSAL • Need to share expensive Instruments (CryoLoad) Sergio Mariotti Göteborg, jun 19th 2006

  17. WHAT can we do ? 2/3 INSTITUTE OF RADIOASTRONOMY, - ITALY UNIVERSITY “TOR VERGATA” - ROME • PROPOSAL: Comparition of Noise Figure Measurementover community (better if even larger) • As the IEEE “Round Robin”, an LNA will be sentto European Laboratories to be measured.Each laboratory will perform measurement asusual and according to its own methodology • Measured data will be compared and published Sergio Mariotti Göteborg, jun 19th 2006

  18. WHAT can we do ? 3/3 INSTITUTE OF RADIOASTRONOMY, - ITALY UNIVERSITY “TOR VERGATA” - ROME Euro Plug • LNA Bandwidth has been chosen to be a bridge between the “easy” 1-18 GHz and the “difficult”over 18 GHz. • Freq. 16 – 26 GHz,Gain=27dB,NF=1.6 dB (130K) Power Supply LNA Sergio Mariotti Göteborg, jun 19th 2006

  19. Essential Bibliography INSTITUTE OF RADIOASTRONOMY, - ITALY UNIVERSITY “TOR VERGATA” - ROME • [1] J. Randa, “Noise Temperature Measurements on wafer” NIST Tech. Note 1390 03/1997 • [2] Agilent Technologies, “Noise Figure measurement accuracy – The Y-Factor method”, Application Note 57-2, 2001. • [3] W.C. Daywitt, “Radiometer equation and analysis of systematic errors for the NIST automated radiometers”, National Institute of Standards and Technology, Technical Note 1327, 03/1989. • [4] C.T. Stelzried, “Temperature calibration of microwave thermal noise sources”, IEEE Transactions on Microwave Theory and Techniques (Correspondence), Vol. MTT-13, No. 1, 01/1965, pp. 128-130. • [5] R.F. Bauer, P. Penfield, “De-Embedding and Unterminating”, IEEE Transactions on Microwave Theory and Techniques, Vol. 22, No. 3, 03/1974, pp. 282-288. • [6] J.D. Gallego, “Accuracy of Noise Temperature Measurement of Cryogenic Amplifiers”, - NRAO Int. Rep. No 285 jan. 1990. Sergio Mariotti Göteborg, jun 19th 2006

  20. Conclusions INSTITUTE OF RADIOASTRONOMY, - ITALY UNIVERSITY “TOR VERGATA” - ROME • The ENR of some Noise Sources has been calibrated. • The Uncertainty related to ENR has been reduced from +/-0.15 dB typ to +/- 0.06 dB typ • Waveguide, millimeter cryoloads are needed to improve reliability • The calibration routine and the instrumental set-up may be repeated once again. Sergio Mariotti Göteborg, jun 19th 2006

  21. Thanks INSTITUTE OF RADIOASTRONOMY, - ITALY UNIVERSITY “TOR VERGATA” - ROME Sergio Mariotti Göteborg, jun 19th 2006

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