A Near-Field Array of Yagi-Uda Antennas for Electromagnetic Susceptibility Testing (open access)

A Near-Field Array of Yagi-Uda Antennas for Electromagnetic Susceptibility Testing

Abstract: In electromagnetic susceptibility testing of electronic equipment, the ideal incident field is a plane wave. To approximate this condition, a seven-element array of Yagi-Uda antennas has been constructed and tested at a frequency of 500 MHz. The element weightings are determined by a near-field synthesis technique which optimizes the uniformity of the field throughout a rectangular test volume in the near field of the array. The amplitude and phase of the electric field have been measured throughout the test volume with a short dipole probe, and the agreement with the theory is excellent.
Date: June 1985
Creator: Hill, David A. & Koepke, Galen H.
System: The UNT Digital Library
Tables of Industrial Gas Container Contents and Density for Oxygen, Argon, Nitrogen, Helium, and Hydrogen (open access)

Tables of Industrial Gas Container Contents and Density for Oxygen, Argon, Nitrogen, Helium, and Hydrogen

Abstract: Custody transfer tables are presented for oxygen, argon, nitrogen, helium, and hydrogen. The tables are based on standard reference data previously compiled by the National Bureau of Standards. Two sets of tables are provided for each fluid. Tables in engineering units cover the range -40 to 130*F with pressures from 100 to 10,000 prig. Tables in SI units (density versus pressure and temperature) cover the range 200 to 370 K with pressures from 0.5 to 70 MPa. The tables in engineering units are designed to provide a means of determining the volume of gas at standard conditions contained in a tank given the volume of the tank and the pressure and temperature of the gas within the tank. The publication also includes four examples of use of the tables in calculating tank quantities.
Date: June 1985
Creator: Younglove, Ben A. & Olien, Neil A.
System: The UNT Digital Library
Transparent Metrology of Signal to Noise Ratios of Noisy Band-Limited Digital Signals (open access)

Transparent Metrology of Signal to Noise Ratios of Noisy Band-Limited Digital Signals

From abstract: I propose the use of a template method for quantitative, correct, and transparent measurement of signal power to additive noise power ratios (SNR) of digital signals and systems under full operating conditions. Outer guard chips of digital templates hold intersymbol interference fixed on inner target chips in realizations of the respective template patterns in traffic. The proposed template method needs to be developed and proven as a potentially valuable metrology capability; it can be especially important for real time online performance assessment and monitoring of digital communication systems.
Date: June 1985
Creator: Halford, Donald
System: The UNT Digital Library