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JNT multiplexer and analog input processor

Conference · · AIP Conference Proceedings (American Institute of Physics); (United States)
OSTI ID:5206415
;  [1];  [2];  [3]
  1. General Electric, 6835 Via Del Oro, San Jose, California (USA)
  2. Analog RF Consulting, 825 Maria Lane, Suite 618, Sunnyvale, California (USA)
  3. DSP Consultant, 278 Carmelita Drive, Mountain View, California (USA)
This paper discusses the design, implementation, and performance of a working model of the Multiplexer-Analog Input Processor (AIP) System for the transmission and measurements of Johnson Noise Power Thermometer sensor information. The goal of this study was to determine the practical circuit limitations, investigate the circuit/component degradations due to radiation, develop an interference cancellation technique, and evaluate the measurements accuracy as a function of temperature, radition, and interference levels. By using a Fast Fourier Transform (FFT) for spectral estimation, the tuned-circuit parameters of the JNT Preamplifiers can be measured and the temperature computed from the power integrated over a limited bandwidth, thereby greatly reducing the system bandwidth requirements and the amplifier noise contamination. Preliminary measurements show that the temperature measurement can be made to {plus minus}10K for temperatures below 1000 K and {plus minus}1% above 1000K, for approximately 1 second of integration time. Multiple interfering signals, down to {ital negative} Signal-to-Interference Ratios (SIR), are eliminated with no significant degradation in the temperature measured. The AIP also adaptively monitors and extracts an estimate of the Preamplifier's noise contribution, eliminating this error from the overall JNT noise power measurement.
DOE Contract Number:
AC03-86SF16006
OSTI ID:
5206415
Report Number(s):
CONF-910116--
Conference Information:
Journal Name: AIP Conference Proceedings (American Institute of Physics); (United States) Journal Volume: 217:3
Country of Publication:
United States
Language:
English