摘要:

Optical technology is playing an expanding role in modern electronic systems. Apart from the much publicized aspects of optical fibre communications, we are currently making use of opto-electronics in television cameras, displays, signal processing and sensors. The address briefly reviews the developing role of opto-electronics and concentrates on the three separate fields of communications, sensors and radar systems. It concludes that the combined power of optics and electronics represents a formidable capability which is still at an early stage of development. The broader impact of such changes within the profession is also touched upon.

DOI:10.1049/ree.1984.0001

出版商:IERE    

年代:1984

数据来源: IET

DOI:10.1049/ree.1984.0002

出版商:IERE    

年代:1984

数据来源: IET

摘要:

A receiver is described that sampled the 1 GHz radio field distribution along a horizontal line of length 32 m. The field distributions were recorded as one-dimensional, offset reference holograms. Computer processing of the holograms formed focused images of scatterers near the line-of-sight path between a c.w. transmitter and the receiving aperture. These images took the form of reconstructed wavefronts, which were further processed by a technique involving complex division and subtraction. Some test results are presented, in which a near-by signal source and an obstacle casting a shadow were imaged.

DOI:10.1049/ree.1984.0015

出版商:IERE    

年代:1984

数据来源: IET

摘要:

The use of the general Bessel-type polynomial for group delay approximation has been investigated and results described. The polynomials yield better results and are superior to those proposed by Johnson and Johnson.

DOI:10.1049/ree.1984.0016

出版商:IERE    

年代:1984

数据来源: IET

摘要:

This paper presents two of the options available for speech encryption. The first is an analogue technique utilizing the principle of time element scrambling but introducing the concept of a sliding window. It is shown that this enables the system time delay to be reduced while simultaneously increasing the number of scrambling permutations available to the user. The second option is a digital technique using a stream cipher. Some of the requirements for such a system are discussed. Finally, the author attempts to show where these two options fit into the range of currently available techniques, from a security viewpoint.

DOI:10.1049/ree.1984.0017

出版商:IERE    

年代:1984

数据来源: IET

摘要:

A linear active RC network with two capacitors is sufficient to realize a 2nd-order transfer function. By making equal the time-constants which consist of one capacitance and the resistance seen across this capacitance with the other capacitance open circuited, minimum network sensitivity can be obtained.

DOI:10.1049/ree.1984.0018

出版商:IERE    

年代:1984

数据来源: IET

摘要:

Several computer hardware description languages (CHDLs) have evolved over the past few years. Some of these languages are simulation oriented. A set of guidelines to compare CHDLs for their simulation attributes is provided in this paper. Eleven CHDLs are compared which range from the earliest description orientated languages to more recent multi-level simulation, fault modelling orientated languages.

DOI:10.1049/ree.1984.0019

出版商:IERE    

年代:1984

数据来源: IET