DOI:10.1049/ecej:19910008

出版商:IEE    

年代:1991

数据来源: IET

摘要:

The Montreal Protocol controls the manufacture and use of substances that deplete the Earth's stratospheric ozone. Amongst the chemicals under regulatory control are two halogenated solvents used widely in the electronics industry: CFC-113 and 1.1.1 trichloroethane. The paper gives the environmental science of ozone depletion and its ecological impact. The properties and uses of the common halogenated solvents are discussed and the range of more environmentally acceptable cleaning options, suitable for the applications in the electronics industry, are given.

DOI:10.1049/ecej:19910013

出版商:IEE    

年代:1991

数据来源: IET

摘要:

Integrated optoelectronic devices are becoming more important as the demand for low-cost devices for sophisticated applications increases. The paper reviews the techniques of bandgap engineering which can be used to control the characteristics of integrated optoelectronic devices fabricated with III-V semiconductors. In particular, the use of quantum wells as active and passive elements in devices such as waveguides, modulators, lasers, and photodiodes is addressed. The flexibility of the performance obtained through the use of quantum wells is emphasised. Linear and nonlinear optical properties as well as the quantum confined Stark effect are discussed. The potential applications and fabrication techniques of lower dimensional semiconductor structures, such as quantum wires, are also described.

DOI:10.1049/ecej:19910014

出版商:IEE    

年代:1991

数据来源: IET

摘要:

The advent of high-speed digital signal processing has revolutionised radio receiver design. The paper describes the design of surveillance receivers based on fast analogue-to-digital conversion and the fast Fourier transform. Several system architectures are discussed and the performance issues which need to be resolved in the design of a receiver are examined. These include bandwidth, dynamic range, and generation of spurious signals.

DOI:10.1049/ecej:19910015

出版商:IEE    

年代:1991

数据来源: IET

摘要:

The paper deals with the future use of the 20/30 GHz satellite communications band, especially with regard to small earth terminals. The 20/30 GHz bands are attractive for private link applications, but are subject to large signal attenuations in the presence of rainfall. Methods to overcome the rain attenuation, known as fade counter-measures, are investigated.

DOI:10.1049/ecej:19910016

出版商:IEE    

年代:1991

数据来源: IET