Showing papers on "Electromagnetic compatibility published in 1973"

Noise in IMPATT-diode oscillators

Abstract: • A submitted manuscript is the version of the article upon submission and before peer-review. There can be important differences between the submitted version and the official published version of record. People interested in the research are advised to contact the author for the final version of the publication, or visit the DOI to the publisher's website. • The final author version and the galley proof are versions of the publication after peer review. • The final published version features the final layout of the paper including the volume, issue and page numbers.

Overview of the Biological Effects of Electromagnetic Radiation

Abstract: A brief review is given of some of the problems concerning the interactions of electromagnetic radiation with biological systems. It is emphasized that we cannot continue to expand the use and power of the electromagnetic spectrum without adequate consideration of its possible biological effects. New research efforts must be started in this area, utilizing a strong and well-coordinated interdisciplinary approach.

Bounds on the Spectrum of a CHIRP Pulse

Abstract: A simple method is described for calculating and plotting strong bounds on the frequency spectra of linear frequency modulated (LFM) pulses used in CHIRP radar transmitters. Bounds on the voltage density (amplitude), energy density, power density, or power spectrum can be hand calculated and plotted in 10 to 20 minutes with a computational accuracy that is adequate for most electromagnetic compatibility (EMC) analyses. The bounds obtained are within one dB of the peaks of the central lobe and major sidelobes. The method is based on the fact that the bounds on the far sidelobes are essentially the same whether or not the pulse is LFM. Several numerical examples are given for Hamming-weighted and trapezoidal pulses. The method is a convenient mathematical tool for engineers involved in compatibility analysis or concerned with radar transmitters complying with military standards pertaining to EMC.

Electromagnetic interference onboard an electrically propelled spacecraft

Abstract: Electric and magnetic interference generated by a power conditioner and ion thruster were measured at JPL. Test results were judged by comparing the measured levels to the levels defined by the solar electric propulsion (SEP) specification that was derived from the existing mission oriented Viking-Orbiter 1975 and Mariner-Jupiter-Saturn 1977 electromagnetic compatibility specifications. In many areas the measured interference was excessive. In some cases, the cause of interference was identified. It was concluded that it should be possible on future designs to improve the EMI characteristics greatly at a modest penalty to weight and efficiency.

Electromagnetic interference of power conditioners for solar electric propulsion

Abstract: Electrical, multikilowatt power conditioning (PC) equipment needed on board a spacecraft utilizing solar electric propulsion creates an electromagnetic environment that is potentially deterimental to the science, navigation, and radio communication hardware. Within the scope of the solar electric propulsion system technology program, three lightweight, 2.5-kW PCs were evaluated in terms of their electromagnetic characteristics. It was found that the levels of radiated and conducted interference exceeded the levels anticipated for a solar electric propulsion mission. These noise emissions, however, were the result of deficient interference design in these models, rather than a basic inability to control interference in this type of PC.

Susceptibility of Electrical Control Systems to Electromagnetic Disturbances

Abstract: The susceptibility of electrical systems to electromagnetic disturbances is mostly specified in the frequency domain. Similarly, the efficiency of suppression techniques, such as filtering and shielding, is also presently specified in the frequency domain. As an appreciable part of the malfunctions (destructive and nondestructive) in control systems is caused by nonrepetitive transient type of electromagnetic disturbances, it is proposed that the susceptibility slhould additionally be specified in the time domain. This is particularly true for control systems containing semiconductor devices, because these devices operate on the principle of minimum clharge injection. Although a transient in the time domain can be mathematically converted into the frequency domain for the purpose of analysis, this procedure does not correspond to the physical situation and therefore does not give the true susceptibility of the system. Finally, several criteria are proposed for specifying the susceptibility of control systems to electromagnetic disturbances.

Load Currents in Missile Circuits Excited by a Plane Polarized Field

Abstract: The writer discusses briefly two simple missile receiving circuits that should provide the reader the insight needed to treat analytically more complicated problems that arise in connection with the electromagnetic compatibility of rockets.