摘要:

A powerful new method of assessing feedback on individual branches representing a transistor is based upon the use of computer-controlled network analysers. Thes-parameters of a transistor, and of the remainder of the amplifier as viewed from the transistor terminals, are measured. These results are converted to admittance matrices. Relations are established between these and the matrix of a multinode circuit diagram, thereby extending the mathematical theory of feedback due to Bode to this method of characterising a physical amplifier operating linearly. The method is described and illustrated by practical applications. The theory is outlined, and aspects of stability margins are considered. The new method advances the practice of feedback assessment. It provides reliable gain and phase margins against self oscillation, total return ratios and components thereof, and sensitivities over frequency ranges as broad as 1-1300 MHz. It does not require special test points, nor circuit diagrams and transistor models. The information obtained gives greater assurance in circuit design, and a tool for use in developments.

DOI:10.1049/ip-g-1.1980.0001

出版商:IEE    

年代:1980

数据来源: IET

摘要:

A capacitor-enhancement network is proposed as a means of reducing the physical dimensions of very low-frequencyRCactive filters. The enhanced capacitor has the advantage that it can be resistively trimmed to yield capacitance values with accuracies similar to those of resistors.

DOI:10.1049/ip-g-1.1980.0002

出版商:IEE    

年代:1980

数据来源: IET

摘要:

The alternating-plane property identifies the roots of a complex polynomial obtained by factorising the denominator of even-degree magnitude-squared transmission-coefficient functions with even-numerator polynomials and reflection zeros constrained to occur in single conjugate pairs at real frequencies in the pass-band. The transfer functions considered in this paper are realisable by Rhodes's physically symmetrical prototype network, and a practical application of the alternating-plane property is to simplify the construction of the admittance function required for the synthesis of the prototype network.

DOI:10.1049/ip-g-1.1980.0003

出版商:IEE    

年代:1980

数据来源: IET

摘要:

In a previous publication it was shown how switched-capacitor (s.c.) networks can be analysed using nodal-charge equations. The result was a description of s.c. networks as time-variant sampled-data networks that led to a 4-port equivalent-circuit representation in theZ-domain. The 4-port representation has been expanded by considering six basic building blocks for the design of a general passive or active s.c. network. In this paper, an indefinite admittance matrix (i.a.m.) method for the analysis of s.c. networks is proposed which uses the 4-terminal admittance matrix of a capacitor in the s.c. network. An algorithm and examples of the proposed method are given.

DOI:10.1049/ip-g-1.1980.0004

出版商:IEE    

年代:1980

数据来源: IET

摘要:

The 20dimensional analysis of tapered distributedRCnetworks using finite elements is described. The accuracy of the method is evaluated by comparing the exact analysis with the results obtained using the finite element method for a uniform network terminated with various parallelRCloads. The 1- and 2-dimensional frequency responses of some exponentially tapered networks are computed to show the error in the conventional assumption of 1-dimensional current flow. The results obtained from the finite element and the 1-dimensional analysis are compared with those obtained experimentally from an exponentially tapered thick-film structure.

DOI:10.1049/ip-g-1.1980.0006

出版商:IEE    

年代:1980

数据来源: IET

摘要:

A systematic study has been made of the patterns of behaviour of the chords and branch elements during the ring-sum operation of two or moref-circuits of a graph, using the edge-numbering convention, which can lead to an efficient algorithm based on vector-space principle for enumeration of all circuits of an undirected graph, which is far superior to the existing ones based on the above principle.

DOI:10.1049/ip-g-1.1980.0007

出版商:IEE    

年代:1980

数据来源: IET