Spectrum analyzer

About: Spectrum analyzer is a research topic. Over the lifetime, 12217 publications have been published within this topic receiving 101851 citations.

Terahertz spectrum analyzer based on a terahertz frequency comb.

Abstract: Precision frequency measurements of terahertz (THz) waves are required to establish metrology in the THz spectral region. However, frequency measurement techniques in this region are immature. We propose a THz spectrum analyzer to measure the absolute frequency and spectral shape of continuous-wave THz waves. Based on a stable frequency comb generated in a photoconductive antenna, the absolute frequency of a sub- THz test source was determined at a precision of 2.8 x 10(-11). Furthermore, the spectral bandwidth of the THz spectrum analyzer can be extended over 1 THz, as demonstrated by measurement of a THz test source. This spectrum analyzer has the potential to become a powerful tool for THz frequency metrology.

High speed power analyzer

Abstract: A method and apparatus for rapidly and continuously sampling AC voltage and current signals in a plurality of power distribution circuits. The sampled signals are then analyzed in a sine board computer to derive the number of fundamental electrical variables. These variables include frequency, RMS volts, RMS amps and a phase angular relationship between the voltage and currents in the system. The computer also performs calibration and compensation functions. From these fundamental variables, other useful parameters can be calculated such as watts, watt-hours, VARS, and power factor.

Physical description of nuclear materials identification system (NMIS) signatures

Abstract: This paper describes all time and frequency analysis parameters measured with a new correlation processor (capability up to 1 GHz sampling rates and up to five input data channels) for three input channels: (1) the 252 Cf source ionization chamber; (2) a detection channel; and (3) a second detection channel. An intuitive and physical description of the various measured quantities is given as well as a brief mathematical description and a brief description of how the data are acquired. If the full five-channel capability is used, the number of measured quantities increases in number but not in type. The parameters provided by this new processor can be divided into two general classes: time analysis signatures and their related frequency analysis signatures. The time analysis signatures include the number of time m pulses occurs in a time interval, that is triggered randomly, upon a detection event, or upon a source fission event triggered. From the number of pulses in a time interval, the moments, factorial moments, and Feynmann variance can be obtained. Recent implementations of third- and fourth-order time and frequency analysis signatures in this processor are also briefly described. Thus, this processor used with a timed source of input neutrons contains all of the information from a pulsed neutron measurement, one and two detector Rossi- α measurements, multiplicity measurements, and third- and fourth-order correlation functions. This processor, although originally designed for active measurements with a 252 Cf interrogating source, has been successfully used passively (without 252 Cf source) for systems with inherent neutron sources such as fissile systems of plutonium. Data from active measurements with an 18.75 kg highly enriched uranium (93.2 wt%, 235 U ) metal casting for storage are presented to illustrate some of the various time and frequency analysis parameters. This processor, which is a five-channel time correlation analyzer with time channel widths as small as 1 ns, was developed at the Oak Ridge National Laboratory and the Oak Ridge Y-12 Plant where it is in use for verification and confirmation of weapons components and other fissile materials in storage and for receipts from other Department of Energy and Department of Defense Facilities.

Frequency hopping spread spectrum passive acoustic wave identification device

Abstract: A system and method for interrogating a passive acoustic transponder, producing a transponder signal having characteristic set of signal perturbations in response to an interrogation signal, comprising a signal generator, producing an interrogation signal having a plurality of differing frequencies; a receiver, for receiving the transponder signal; a mixer, for mixing the transponder signal with a signal corresponding to the interrogation signal, to produce a mixed output; an integrator, integrating the mixed output to define an integrated phase-response of the received transponder signal; and an analyzer, receiving a plurality of integrated phase-responses corresponding to the plurality of differing frequencies, for determining the characteristic set of signal perturbations of the passive acoustic transponder.