摘要:

An improved version of the Kaiser method for the design of nonrecursive 1-dimensional digital filters, and a method for the design of recursive 1-dimensional digital filters due to Antoniou are applied to the design of 2-dimensional digital filters. Two methods are developed which can be used to design lowpass filters satisfying prescribed amplitude-response specifications. The two methods are easy to apply, and entail a minimal amount of computation.

DOI:10.1049/ip-g-1.1981.0012

出版商:IEE    

年代:1981

数据来源: IET

摘要:

Dithering the coefficients of digital filters enhances the selection of available transfer functions when the coefficient word length is limited. Furthermore, dithering can reduce limit cycle oscillations. However, noise is introduced into the filter. This paper presents a novel analytic technique for determining the noise components introduced by dithering. It uses time-squared transfer functions to produce generalised expressions for the introduced noise. These expressions increase the potential for exploiting the advantages of randomly dithering coefficients in digital filters. Furthermore, the analysis can be applied to continuous systems.

DOI:10.1049/ip-g-1.1981.0013

出版商:IEE    

年代:1981

数据来源: IET

摘要:

We consider in this paper the derivation of input equivalent noise voltages and currents for both feedback and nonfeedback amplifier configurations. In the case of feedback amplifiers, a greatly simplified, approximate analysis is utilised and the accuracy of the approximation established. For low-noise amplifiers, a systematic design approach based on input equivalent noise sources is outlined. The relationship between the dual-input equivalent noise voltage and current sources is also established and a design example presented.

DOI:10.1049/ip-g-1.1981.0014

出版商:IEE    

年代:1981

数据来源: IET

摘要:

A new stabilisation procedure is presented, based on the spectral factorisation in the cepstrum domain. Pistor's stability criterion is used for the stability of the resulting filter. It is shown that any unstable causal 2-dimensional filter function can be decomposed into stable filters that recurse in a halfplane. The new procedure has been compared with the planar least-squares inverse of Shanks and the discrete Hilbert transform of Read and Treitel. It has been found that the present stabilisation technique has a better frequency response approximation than the existing ones. The method is therefore an attractive alternative to the least-squares procedure and the discrete Hilbert transform method.

DOI:10.1049/ip-g-1.1981.0015

出版商:IEE    

年代:1981

数据来源: IET

摘要:

A new approach to the perturbation theory of linear systems is developed and is applied to the computerised generation of symbolic functions. The function is defined in terms of increments to, rather than, the element values themselves. The modification leads to considerable theoretical and computational simplifications. Both the frequency and the increments can be symbols in the function.

DOI:10.1049/ip-g-1.1981.0016

出版商:IEE    

年代:1981

数据来源: IET

摘要:

Widespread use of resistively terminatedLCladder prototypes reflects their excellent passband magnitude sensitivity, although it is known that this is exceeded by the phase sensitivity. In the paper, a bound is derived for the ratio of the magnitude and phase sensitivity, which leads to a quantitative assessment of the relative contributions of component tolerance and parasitic loss in response deviation from the nominal filter characteristic.

DOI:10.1049/ip-g-1.1981.0017

出版商:IEE    

年代:1981

数据来源: IET

摘要:

The paper examines the use of the multiplying digital-to-analogue convertor (DAC) in op-amp inverting summers and integrators. The digitally controlled analogue filtering circuits are obtained when analogue computer-typeRCfilters are implemented with digitally controlled summers and integrators. An example of a fully programmable state variable bandpass filter is outlined.

DOI:10.1049/ip-g-1.1981.0018

出版商:IEE    

年代:1981

数据来源: IET

摘要:

The control of dynamic range and resolution in the conversion of the voltage and current signals on whose measurement depends the operation of a modern electronic component meter or ‘bridge’ is a major problem in design. The paper presents a modified form of dual-slope analogue-to-digital convertor for this purpose. Called adaptive acquisition time (AAT) conversion, the technique directly produces a floating-point binary output representation of the signal for subsequent computation purposes. The AAT convertor leads to a bridge range design procedure resulting in a maximum variation of convertor counts of only 2.1 over the entire resistance range of the instrument from 0.5 Ω to 8 MΩ. The design of the excitation circuit resulting from the use of AAT conversion itself leads to an autoranging system faster in operation than conventional step-by-step methods. A technique for reducing the sensitivity of the integrator to timing errors in the acquisition period when unfiltered signals.

DOI:10.1049/ip-g-1.1981.0019

出版商:IEE    

年代:1981

数据来源: IET