DOI:10.1049/ree.1973.0096

出版商:IERE    

年代:1973

数据来源: IET

摘要:

This paper presents a review of the state of the art of optical fibres and their potential use as waveguides for long-distance transmission of light. The physical principle of light guidance in fibres is discussed and the advantages and short comings of fibres are pointed out. The properties of single and multimode fibres are reviewed.

DOI:10.1049/ree.1973.0097

出版商:IERE    

年代:1973

数据来源: IET

摘要:

The paper reviews the demands made on technology by the potential impact of fibre-optical communication systems. The reasons for the interest in this technology are discussed in terms of discounted cash flow for wideband transmission installation. The primary system requirements are identified and research aimed at developing fibre-optic cable, light sources and terminal sub-systems is described.Some typical system parameters which can reasonably be related to the present state of art are given. It is concluded that there is now little doubt that fibre optic communication will make a major impact on transmission technology. It is further suggested that the greatest impact may be in opening up new fields of telecommunication.

DOI:10.1049/ree.1973.0098

出版商:IERE    

年代:1973

数据来源: IET

摘要:

A glass-fibre communications system using travelling-wave amplifiers operating on the laser principle is studied. The propagation characteristics of such a system are investigated theoretically with the aid of the mean value and variance of the statistical distribution of the number of photons. When linear optical amplifiers are used, the noise increases at each stage on account of spontaneous emission in the amplifier, thereby limiting the length of the transmission range. The maximum transmission range increases with the magnitude of the input signal and decreases with the gain per stage and the number modes.

DOI:10.1049/ree.1973.0099

出版商:IERE    

年代:1973

数据来源: IET

摘要:

An analysis is given of propagation in multimode optical fibres having finite transmission loss. Using experimentally-deduced values for the cladding loss, fibre dispersions are calculated for a range of input beam widths and are compared with experiment. It is shown that the core loss has little effect on dispersion. Cladding loss reduces dispersion for a relatively small increase in attenuation, while dispersion and attenuation become non-linear functions of length.

DOI:10.1049/ree.1973.0100

出版商:IERE    

年代:1973

数据来源: IET

摘要:

To avoid blind speed phenomena, staggered-p.r.f. m.t.i. systems are used in modern radars for detection of high-speed targets. In this paper a procedure is presented which considers both the effect of filter weights and the interpulse durations. The goal of this procedure is to yield an m.t.i. response with minimum variations in the pass-band and maximum attenuation in the stop-band.

DOI:10.1049/ree.1973.0101

出版商:IERE    

年代:1973

数据来源: IET

摘要:

An approximate analysis of the Rao–Newcomb gyrator circuit is presented. It is justified by comparison of its predictions for the y-parameters of the gyrator with predictions based on computation by general-circuit-analysis program and with predictions based on admittance measurements. The unconditional stability, passivity and performance Jimitations of the gyrator are discussed.

DOI:10.1049/ree.1973.0102

出版商:IERE    

年代:1973

数据来源: IET