DOI:10.1049/ree.1979.0095

出版商:IERE    

年代:1979

数据来源: IET

摘要:

The determination of the atmospheric extinction coefficient is necessary to allow visual range to be calculated. The limitations of nephelometers (devices which measure light scattered in the atmosphere) are discussed. These limitations lead to the conclusion that optical transmissometers are the only valid devices for assessing extinction coefficients. New techniques for maintaining the accuracy of transmissometers over many months of use are described. The high accuracies achieved allow a wide dynamic range of visibility to be measured with a single base line instrument.

DOI:10.1049/ree.1979.0100

出版商:IERE    

年代:1979

数据来源: IET

摘要:

As the number of transmitters in operation in the broadcasting network is increased, so there is an everincreasing requirement to provide more sophisticated test and monitoring equipment. To meet this need, the IBA has developed three equipments, the tunable receiver, tunable demodulator and tunable test transmitter. The requirements, equipments, design and application are discussed in this paper.

DOI:10.1049/ree.1979.0101

出版商:IERE    

年代:1979

数据来源: IET

摘要:

In 1971 the Council of the European Economic Community agreed in principle to the planning of a computer network to enable data terminals located in any of the member countries to gain on-line access to scientific, technical and socio-economic information held on data bases at specific locations. In 1974 the Commission issued a three-year action plan which included the establishment of a computer network which became known as EURONET. More recently the term EURONET has become associated with the Telecommunications Network alone and, for aspects concerning the terminals and the data bases, the name DIANE—Direct Information Access Network EUROPE—has been adopted. The EEC EURONET organization is described in the paper and also the involvement of the CEPT (Conference of European Postal and Telecommunications Administrations) and of the individual Administrations.The basic specification, and the network configuration to meet it, are given together with those factors affecting the choice of packet-switching.Following a description of the hardware and software to be used, including alignment with CCITT (International Telegraph and Telephone Consultative Committee) Recommendations, an assessment is made of the likely future enhancement of EURONET, after its planned opening in 1979, and of the work undertaken by the Commission to standardize data base access and retrieval procedures.

DOI:10.1049/ree.1979.0102

出版商:IERE    

年代:1979

数据来源: IET

摘要:

Serial two's complement pipeline multipliers are the basic module in the serial arithmetic implementation of digital signal processing algorithms. These multipliers accept the data serially in two's complement notation and generate a serial output product in two's complement notation as well. The designs, however, presented up to now lack in modularity; in addition, they have the problem of the internal overflow. In this paper a new two's complement multiplication algorithm is worked out, that allows cellular implementation of serial-pipeline multipliers and does not limit the dynamic range of the data input. In addition, by using the proposed cell, useful functions for digital signal processing can be performed. Methods are proposed for overflow detection, and comparison is made with previously proposed realizations.

DOI:10.1049/ree.1979.0103

出版商:IERE    

年代:1979

数据来源: IET

摘要:

Very-high-speed silicon-on-sapphire (s.o.s.) n–channel m.o.s.f.e.t.s have been fabricated which demonstrated a maximum oscillating frequency of approximately 6-4 GHz. These m.o.s.f.e.t.s—test transistors on an integrated circuit—were fabricated with a process which can be used to fabricate high–speed integrated circuits. Spacecraft data processing requirements are evolving to indicate the need for very-high-speed devices which are capable of being integrated into large–scale circuits. Improvements in high-speed data processing communications systems are badly needed. Many of these applications will be met be very-high-speed s.o.s.integrated circuits.

DOI:10.1049/ree.1979.0104

出版商:IERE    

年代:1979

数据来源: IET

摘要:

A general circuit configuration is presented from which two bandpass and two lowpass filters can be derived as special cases. These are partially active R filters since each filter has one capacitor and realizes a second-order function by making use of an amplifier pole.

DOI:10.1049/ree.1979.0105

出版商:IERE    

年代:1979

数据来源: IET