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Electronically controlled oscillator with linear frequency adjusting for four‐phase or differential quadrature output signal generation
Author(s) -
Sotner Roman,
Herencsar Norbert,
Jerabek Jan,
Koton Jaroslav,
Dostal Tomas,
Vrba Kamil
Publication year - 2014
Publication title -
international journal of circuit theory and applications
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.364
H-Index - 52
eISSN - 1097-007X
pISSN - 0098-9886
DOI - 10.1002/cta.1919
Subject(s) - control theory (sociology) , capacitor , output impedance , amplifier , resistor , automatic gain control , electrical impedance , vackář oscillator , rc oscillator , oscillation (cell signaling) , electronic engineering , voltage , cmos , engineering , computer science , electrical engineering , voltage controlled oscillator , control (management) , artificial intelligence , biology , genetics
This paper introduces novel four‐phase oscillator employing two Dual‐Output Controlled Gain Current Follower Buffered Amplifiers (DO‐CG‐CFBAs), single Current Amplifier, three resistors, and two grounded capacitors suitable for differential quadrature signal production (floating outputs). To control the frequency of oscillation (FO) and condition of oscillation (CO), only the current gain adjustment of active elements is used. The circuit was designed by well‐known state variable approach. The oscillator employs three active elements for linear control of FO and to adjust CO and provides low‐impedance voltage outputs. Furthermore, two straightforward ways of automatic amplitude gain control were used and compared. Active elements with very good performance are implemented to fulfill required features. Suitable CMOS implementation of introduced DO‐CG‐CFBA was shown. Important characteristics of the designed oscillator were verified experimentally and by PSpice simulations to confirm theoretical and expected presumptions. Copyright © 2013 John Wiley & Sons, Ltd.