DOI:10.1049/ree.1979.0001

出版商:IERE    

年代:1979

数据来源: IET

DOI:10.1049/ree.1979.0002

出版商:IERE    

年代:1979

数据来源: IET

摘要:

Some idea of the magnitude of the problem of electromagnetic interference and methods of its propagation on board ship are given. The present situation relating to marine e.m.c. specifications is described and the need for agreed and accepted marine e.m.c. specifications, not only nationally but internationally, is proposed. Present installation techniques and measures used to minimize interference on commercial marine installations is given. Specific examples of interference at sea are quoted and some details of a proposed I EC specification are listed. An example is given of the e.m.c. design of a compact radio telephony equipment.

DOI:10.1049/ree.1979.0006

出版商:IERE    

年代:1979

数据来源: IET

摘要:

A description of SEMCAP (Specification and Electromagnetic Compatibility Analysis Program) is given. The program uses mathematical models of interference generators and receptors and of the indirect transfer mechanisms linking them. The program calculates the voltage received at the receptor through capacitive, inductive, E– and H–field coupling. The application of the program to the Orbital Test Satellite is described. The accuracy, limitations and cost effectiveness of the program are discussed.

DOI:10.1049/ree.1979.0007

出版商:IERE    

年代:1979

数据来源: IET

摘要:

The fundamental phenomena involved in the screening of braided cables are discussed and knowledge of these is shown to aid in improving this screening as expressed in terms of surface transfer impedance. It is shown how the use of magnetic materials between two braids, coupled with knowledge of the above optimization techniques, can lead to enormously improved screening which can be maintained by proper application of the magnetic tape.

DOI:10.1049/ree.1979.0008

出版商:IERE    

年代:1979

数据来源: IET

摘要:

Operating a man-portable radar set in a battlefield forward area or in a civil application presents wide variations in the frequency distribution of other services which may affect the equipment or be affected by it. Analysis of typical operational situations was undertaken to quantify the problems and develop a specification. Measurements on development models are described, together with the solutions adopted to meet the requirement.

DOI:10.1049/ree.1979.0009

出版商:IERE    

年代:1979

数据来源: IET

摘要:

An adaptive delta sigma modulator (ADSM) is proposed wherein the companding is done in a novel fashion. The output of a simple DEM is differentiated, and the resulting waveform is filtered in a syllabic filter after d.c. restoration. This yields a control signal that is proportional to the average number of transitions from one to zero and zero to one that occur at the coder output. The signal so obtained is inversely proportional to the input amplitude and can then be used to control the pulse height in the feedback path. At 40 kHz, the s.n.r. is greater than 21 dB over an input range of 30 dB with a peak s.n.r. of 24 dB (the input being a 800 Hz sinusoid). The s.n.r. is almost constant over the message band and improves at a rate of about 8 dB/octave increase in the clock rate.

DOI:10.1049/ree.1979.0010

出版商:IERE    

年代:1979

数据来源: IET