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Precise Electronically Adjustable Oscillator Suitable for Quadrature Signal Generation Employing Active Elements with Current and Voltage Gain Control

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Abstract

A new oscillator suitable for quadrature and multiphase signal generation is introduced in this contribution. A novel active element, called the controlled gain-buffered current and voltage amplifier (CG-BCVA) with electronic possibilities for current and voltage gain adjustment is implemented together with a controlled gain-current follower differential output buffered amplifier (CG-CFDOBA) for linear adjustment of the oscillation frequency and precise control of the oscillation condition in order to ensure a stable level of generated voltages and sufficient total harmonic distortion. The parameters of the oscillator are directly controllable electronically. Simultaneous changes of two current gains allow linear adjusting of the oscillation frequency, and a controllable voltage gain is intended to control the oscillation condition. A detailed comparison of the proposed circuits with recently developed and discovered solutions employing the same type of electronic control is provided and shows the useful features of the proposed oscillator and utilized methods of electronic control. Behavioral models based on commercially available ICs have been used for experimental purposes. CMOS implementation of active elements was introduced and utilized for additional simulations and studies. Non-ideal analysis, Monte Carlo statistical evaluations of simulated models, and further analyses were performed for the exact determination of the expected results. Laboratory experiments confirmed the workability and estimated behavior of the proposed circuit as well.

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Acknowledgements

The research described in this paper was supported by Czech Science Foundation projects under No. 102/09/1681 and No. 102/11/P489, by the project (Brno University of Technology) of specific research FEKT-S-11-15 and the project Electronic-biomedical co-operation ELBIC M00176. Dr. Herencsar was supported by the project CZ.1.07/2.3.00/30.0039 of the Brno University of Technology. The support of the project CZ.1.07/2.3.00/20.0007 WICOMT, financed by the operational program Education for Competitiveness is gratefully acknowledged. The described research was performed in laboratories supported by the SIX project, registration number CZ.1.05/2.1.00/03.0072, the operational program Research and Development for Innovation. This research work is also funded by projects EU ECOP EE.2.3.20.0094 and CZ.1.07/2.2.00/28.0062.

The authors also wish to thank the anonymous reviewers for their useful and constructive comments which have helped to improve the paper.

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  1. Department of Radio Electronics, Faculty of Electrical Engineering and Communication, Brno University of Technology (BUT), Technicka 3082/12, Brno, 616 00, Czech Republic

    Roman Sotner & Zdenek Hrubos

  2. Department of Telecommunications, Faculty of Electrical Engineering and Communication, Brno University of Technology (BUT), Technicka 3082/12, Brno, 616 00, Czech Republic

    Norbert Herencsar, Jan Jerabek & Kamil Vrba

  3. Department of Electronics and Computer Science, College of Polytechnics Jihlava, Tolsteho 16, Jihlava, 586 01, Czech Republic

    Tomas Dostal

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Sotner, R., Hrubos, Z., Herencsar, N. et al. Precise Electronically Adjustable Oscillator Suitable for Quadrature Signal Generation Employing Active Elements with Current and Voltage Gain Control. Circuits Syst Signal Process 33, 1–35 (2014). https://doi.org/10.1007/s00034-013-9623-2

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