摘要:

Active filters that derive their frequency response from internal amplifier dynamics, but use no external capacitors in their implementation, are referred to as “activeR” filters. Because of their potential advantages in terms of miniaturisation (i.e. fabrication), ease of design and high-frequency performance, these circuits are receiving increasing attention in the technical literature. The paper reviews the published synthesis procedures for 1st-, 2nd- and higher-order active R filters; it is shown that the 1st- and 2nd-order circuits developed to date are special cases of a general activeRtopology. The paper discusses nonideal aspects and limitations of active R filter performance, which arc usually neglected in the literature; in particular, the potentially severe effect of temperature-induced drift in the amplifier's dynamic response is considered, and methods of drift compensation are discussed. Experimental results are presented to verify filter performance and the theoretical derivations

DOI:10.1049/ij-ecs.1978.0022

出版商:IEE    

年代:1978

数据来源: IET

摘要:

Systematic methods for synthesising nonlinear networks having a prescribed scalar or multidimensional piecewise-linear function are described. In the scalar case, precision active-circuit building blocks using operational amplifiers, transistors, diodes, and resistors are given for realising piecewise-linear drivingpoint and transfer characteristic plots. In the multidimensional case, methods are given for realising a multiterminal nonlinear network having a multidimensional piecewise-linear transfer function. Finally, these methods are generalised for synthesising nonlinearn-ports having a prescribed multidimensional piecewiselinear driving-point function. Although most of the basic building blocks are grounded active networks, convertor networks are developed for transforming such grounded networks into floating networks having the same properties. By slight modifications of these convertor networks, other useful conversion properties are also presented

DOI:10.1049/ij-ecs.1978.0023

出版商:IEE    

年代:1978

数据来源: IET

摘要:

A voltage-controlled oscillator (v.c.o.) circuit using single-channel m.o.s technology is described. The theory of operation of the v.c.o. is presented and the design criteria arc discussed. The results obtained on the experimental integrated circuit fabricated using single-channel lateral V-m.o.s. technology show good agreement with the theory and with the results obtained from computer simulation. The circuit described results in an economical and simple v.c.o. that may be useful in a variety of applications

DOI:10.1049/ij-ecs.1978.0024

出版商:IEE    

年代:1978

数据来源: IET

摘要:

A monolithic digital-correlator circuit design is proposed and described which uses four-valued or quad threshold logic to develop its binary coded output. The use of four-valued logic provides a reduced device count, fewer signal lines and a reduced chip area. This design is compared to a conventional all-binary design of the same digital correlation function

DOI:10.1049/ij-ecs.1978.0025

出版商:IEE    

年代:1978

数据来源: IET

摘要:

A comprehensive set of results are presented for a variety of surface targets. The targets chosen range from −40 dBm2to + 70 dBm2and results of the smaller ones have been compiled from trials that have taken place over a variety of environmental conditions. These illustrate the variability experienced at sea in the radar performance of targets, which, in a free-space environment, may exhibit neither fading nor variability with the aspect viewed. The necessary statistical treatment for fading targets has been used to describe the targets examined in a manner which is directly applicable to the estimation of radar range and detection probabilities. Most of the results are appropriate to the bulk of marine radars using a wavelength of 3.2 cm and horizontally-polarised transmission and reception

DOI:10.1049/ij-ecs.1978.0026

出版商:IEE    

年代:1978

数据来源: IET