%0 Journal Article
%T Voltage-Mode Four-Phase Sinusoidal Generator and Its Useful Extensions
%A Sudhanshu Maheshwari
%J Active and Passive Electronic Components
%D 2013
%I Hindawi Publishing Corporation
%R 10.1155/2013/685939
%X This paper introduces a new voltage-mode second-order sinusoidal generator circuit with four active elements and six passive elements, including grounded capacitors. The frequency and condition of oscillation can be independently controlled. The effect of active element¡¯s nonidealities and parasitic effects is also studied; the proposed topology is good in absorbing several parasitic elements involved with the active elements. The circuit is advantageous for generating high frequency signals which is demonstrated for 25£¿MHz outputs. Several circuit extensions are also given which makes the new proposal useful for real circuit adoption. The proposed theory is validated through simulation results. 1. Introduction Four-phase sine-wave generators with voltage outputs progressively separated by 90¡ã apart find useful applications in communication and instrumentation systems and hence have been well covered in open literature [1¨C4]. Some of the earlier works based on transconductance- approach [1] offered compact realization with low transistor counts, but limited in frequency when compared to current conveyor based works [2]. Very novel addition to the literature witnessed compact bread-boarding solutions with scope of future integration of new active elements, like DO-CIBA [3]. Meanwhile, traditional approach of employing band-pass filter for quadrature oscillator realization, capable of generating four-phase outputs, continues to attract recent attention [4]. The four-phase voltage-mode circuit of [5] uses five opamps and five passive components, most of which are in floating form. The works as mentioned so far [1¨C5] falls in the category of second-order networks. Another variety of circuits employed third-order networks to generate quadrature voltage outputs, with a possibility of extension to four phases by additional active elements [6]. The active- network of [6] used current controlled conveyors and three capacitors. Though the circuit in [6] was intended to generate four-phase current outputs, two quadrature voltage outputs were simultaneously available, a fact not mentioned therein. The discussion on quadrature oscillators¡¯ review is worth a voluminous work and can be restricted here, in view of a recent work [3, and cited therein]. In spite of this restriction, there are many works which find mention for their value, without belittling hundreds of other works, not mentioned herein [7¨C14]. For instance the work in [10] was a first attempt to use DVCC for oscillator application. Another work later [11] presented voltage-mode quadrature oscillator
%U http://www.hindawi.com/journals/apec/2013/685939/