摘要:

The ‘balanced mixer’, when used as a phase detector in phase-locked loops, can exhibit varying characteristics, which depend mainly on the ratio of the input signal level and the imbalance factor. In the paper, the effect of using imbalanced mixers in phase-locked loops on the acquisition behaviour of the loop has been investigated. A formula that describes the acquisition boundaries of the loop has been obtained for the general case, when an imbalanced detector of various characteristics is used. This formula compares very well with well known special cases of detector characteristics, such as those given by sinusoidal or triangular relationships.

DOI:10.1049/ip-g-1.1985.0026

出版商:IEE    

年代:1985

数据来源: IET

摘要:

A recursive fixed-memory filter is developed to fit a first-order polynomial to equally spaced measurements. The parameters of the filter are determined using a weighted least-squares performance index. The recursive and the nonrecursive realisations of the fixed-memory filter are compared, and the effects of the weighting coefficient on stability, noise performance and frequency response are discussed. It is shown that, by a proper selection of the weighting coefficient, the performance of the filter is improved.

DOI:10.1049/ip-g-1.1985.0027

出版商:IEE    

年代:1985

数据来源: IET

摘要:

The paper is addressed to solve the synthesis problem for a class of nonlinear resistive one-port networks. We will deal with the class of piecewise polynomial networks and give a set of basic components needed for the synthesis of these networks. This is the preceding step required for synthesising nonlinearn-port networks.

DOI:10.1049/ip-g-1.1985.0028

出版商:IEE    

年代:1985

数据来源: IET

摘要:

The Monte Carlo method applied to the circuit tolerance analysis problem has the attraction of insensitivity to the number of toleranced components, but is computationally expensive. However, its efficiency can be improved by exploiting variance reduction techniques. The paper describes a novel application and development of one such technique, namely the control variate method. The paper outlines the standard Monte Carlo method and introduces the control variate procedure. The estimation of circuit properties such as yield, yield sensitivities and moments of performance function distributions are described. The control variate method requires the introduction of a circuit which we call the shadow model, whose performance approximates that of the circuit under consideration, but is much cheaper to analyse. We present experimental results for a particular circuit example and its shadow model and make suggestions for the general construction of shadow models.

DOI:10.1049/ip-g-1.1985.0030

出版商:IEE    

年代:1985

数据来源: IET

摘要:

For a class of weakly nonlinear autonomous systems exhibiting both resistive and reactive nonlinearities, asymptotic orbital stability is investigated through a new narrow-band differential approach. The main result is the derivation of the exact characteristic polynomial associated with the local dynamics of the amplitude and phase of the free-running oscillation to be tested. For annth-order circuit, (n– 1) necessary and sufficient stability conditions are then obtained, in an analytical explicit form suitable for computer implementation, by resorting to conventional Hurwitz test algorithms. A comparison with other differential stability criteria available in the literature is also carried out. As an example, a double-tuned oscillator is finally investigated.

DOI:10.1049/ip-g-1.1985.0031

出版商:IEE    

年代:1985

数据来源: IET

摘要:

The bucket-brigade charge transfer principle can be used to design a switched capacitor integrator without using operational amplifiers. This integrator can replace the conventionalRC-active integrator of the dual-slope convertor. When combined with a regenerative comparator circuit, a compactA/Dconvertor can be fabricated using conventional NMOS technology.

DOI:10.1049/ip-g-1.1985.0032

出版商:IEE    

年代:1985

数据来源: IET

摘要:

A comprehensive study for generation and design of grounded-capacitor variable-frequency RC-active oscillators using operational amplifiers (OAs) is reported. All the circuits derived are canonic, that is, the number of components (active as well as passive) in them is a minimum. First, a set of eight canonic circuits is found, each using one OA, two capacitors and six resistors. However, these circuits suffer from either a poor start-up property or a limited frequency range of variation. Thus, based on this set of eight circuits, another set of 12 variable-frequency oscillators is derived. This set provides easy tunability and a wider tuning range. Both the sets are shown to be complete. All the variable-frequency oscillators are single resistor controlled. Two of the circuits have their variable resistors grounded which makes them attractive candidates for voltage-controlled oscillators. Design equations for all the oscillator circuits are given. All the circuits have been laboratory tested. Experimental results are found to be in close agreement with the theoretical analysis. Representative test results are included in the article.

DOI:10.1049/ip-g-1.1985.0033

出版商:IEE    

年代:1985

数据来源: IET

摘要:

A procedure is developed for the design of amplifiers to meet specified gain and bandwidth figures. The number of required operational amplifier stages is minimised. A figure of merit is introduced to determine if a particular operational amplifier can be used to satisfy a given set of specifications.

DOI:10.1049/ip-g-1.1985.0034

出版商:IEE    

年代:1985

数据来源: IET