Spectrum analyzer

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

Indoor and outdoor frequency measurements for MM-waves in the range of 60 GHz

Abstract: Using a spectrum analyzer and synthesized signal generator, several measurements for the frequency-domain characterization of the radio channel in the 60 GHz band were performed. In the experiments, a carrier wave (CW) was swept with a constant amplitude across the 100 MHz band, centered around 59.9 GHz. The channel frequency response was measured at the receiver side. The results can be used for the design of an OFDM (orthogonal frequency division multiplex) system. The measurement environments were a corridor and a big college room in a high-rise office building (indoor) and a parking site and a grassfield at the side of that building (outdoor). The spectrum samples were taken in each of the environments. From such samples, it is possible to calculate the Rice parameter k and the path loss coefficients. It was necessary to the develop an appropriate measurement analysis, stemming from the fact that the spectrum analyzer gives no information on the phase, only amplitude. Measurement analysis method and results are explained.

Refraction contrast in X-ray imaging

Abstract: A two-crystal diffractometer in the non-dispersive configuration is used for measurement of the effects of refraction in weakly absorbing test objects. Characteristic Ka1 radiation from a fine-focus X-ray tube with Mo anode is used. The probing beam is about 70mm wide and 3 mm high. The sample is placed between the monochromator and analyzer, and it is scanned through the beam. The analyzer is tuned to reflect at the low-angle slope, at the top, or at the high-angle slope of the rocking curve, when the sample is not in the beam. Refraction changes the angle of incidence on the analyzer causing changes in intensity. The observed intensity distributions are exactly reproduced by a calculation, where only the effects of refraction are included. The effects of in-beam interference are negligible or very small, which is also verified by changing the distance between the object and the detector. r 2002 Elsevier Science B.V. All rights reserved.

Radio frequency digital fourier analyzer

Abstract: A radio frequency digital Fourier analyzer is provided which serves not only as a spectrum analyzer, but as an important statistical tool. The digital Fourier analyzer comprises a twochannel receiver which is interfaced with a digital computer through an analog/digital converter, and which also includes appropriate control, peripheral and read-out equipment. The receiver comprises a two-channel radio frequency/intermediate frequency converter, and it can operate as an analog spectrum anaylzer or network analyzer. The receiver responds to radio frequency signals in a frequency range of, for example, 500 KHz to 1,300 MHz. The receiver converts a radio frequency signal which is to be analyzed into a band-limited intermediate frequency signal of the proper frequency for digital conversion. The analog/digital converter converts the intermediate frequency signal from the receiver into digital data for the computer. The computer calculates the fast Fourier transform (FFT) of the sampled data and uses the result to calculate one or more desired functions. The read-out equipment displays and/or records the results of the computation.

A rudimentary electron energy analyzer for accelerator diagnostics

Abstract: We have constructed a compact, planar retarding field analyzer for the diagnostics of low-energy, background electrons in a high-energy particle accelerator. Bench measurements of the analyzer have been made to characterize it, and the results are reasonable in light of models of this type of analyzer. Comparisons to results obtained using a beam-position monitor (BPM) show the advantages of this analyzer for electron diagnostics. Sample results from analyzers installed at the Advanced Photon Source storage ring at Argonne National Laboratory and the Proton Storage Ring at Los Alamos National Laboratory show how the analyzers can be used for studying the intensity, energy, and time structure of electrons in an accelerator environment.