Some observations on single-element control sine-wave oscillators

Abstract

A new generuilired approach to the study of tho variable frequency sine-wave oscillators in active RC filters having o ainglo.element control facility is presented. The oonetraints on the filter functions which are amenablo for genoration of such oscillations with feedback are derived and o number of exemplary circuits are given and also their frequency and gain limits in tables. The oacillotion atobility ia also studied following Loeb's criterion of limit cyolo stability for syetema having ~aturation oharacteriatics in the active parts. Tho circuits om also shown to yield VCO' s with voltage controlled F E T ns tho frequency controlling pnmmater. Tho possiblo configurations of tho amplifier circuits with operntional amplifiers aa the building blook are considered inoluding s discussion on bandwidth limitation.

Analysis, Synthesis and Design of New Types of RC-Active Sinusoidal Oscillators (Part I)

“…el and R e2 both by electronically realised linear voltage-controlled-resistances (VCR) described in [15] (driven by the same control voltage), the oscillators of type 1 would make it possible to design truly linear sinusoidal voltage-controlledoscillators (VCO) which are required in many analogue systems such as analogue phase-locked-loops, frequency-response display systems etc. This feature is particularly notable in view of the fact that sinusoidal VCOs based upon the known types of oscillators (for example see [4] and [5] and the references cited therein) do not yield linear f/v characteristics.…”

“…During the past three decades a large number of papers have been published in technical literature on the problems relating to the analysis and synthesis of sinusoidal oscillators and a multitude of circuits have so far been developed using many different kinds of active elements such as bipolar transistors, FETs [1], op-amps (see [2][3][4][5][6][7][8][9] and references therein) and relatively newer elements such as current-conveyors [10,11] and DVCCS/DVCVS or OTA [12,13] etc. The present paper is different from these earlier publications in that it introduces new types of oscillators which promise to offer many novel features and practical advantages not available in previously published sinusoidal active-RC oscillators.…”

Operational amplifier-based voltage-controlled oscillator

“…Over the past few years a lot of work has been done to develop oscillator circuits advantageous from the viewpoint of microelectronic fabrication (Holt and Lee 1967, Patranabis 1970, Patranabis and Sen 1970, Sun 1972, Dutta Roy 1976, Genin 1975, Tripathi et al 1977, Soliman and Awad 1978, Ahmed 1977, Hribsek and Newcomb 1976, Sundaramurthy et a / . 1977, Bhattacharyya and Natarajan 1977, Senani 1979, Martinez Martinez et al 1984.…”