Table of Contents
International Scholarly Research Notices
Volume 2015, Article ID 690923, 7 pages
Research Article

Electronically Tunable Differential Integrator: Linear Voltage Controlled Quadrature Oscillator

1Department of Electronics & Telecommunication Engineering, Jadavpur University, Kolkata 700032, India
2Department of Electronics & Communication Engineering, Narula Institute of Technology, Kolkata 700109, India
3Department of Electronics Engineering, B. P. P. Institute of Technology, Kolkata 700052, India

Received 15 December 2014; Revised 22 March 2015; Accepted 26 March 2015

Academic Editor: Stephan Gift

Copyright © 2015 Rabindranath Nandi et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


A new electronically tunable differential integrator (ETDI) and its extension to voltage controlled quadrature oscillator (VCQO) design with linear tuning law are proposed; the active building block is a composite current feedback amplifier with recent multiplication mode current conveyor (MMCC) element. Recently utilization of two different kinds of active devices to form a composite building block is being considered since it yields a superior functional element suitable for improved quality circuit design. The integrator time constant and the oscillation frequency are tunable by the control voltage of the MMCC block. Analysis indicates negligible phase error for the integrator and low active -sensitivity relative to the device parasitic capacitances. Satisfactory experimental verifications on electronic tunability of some wave shaping applications by the integrator and a double-integrator feedback loop (DIFL) based sinusoid oscillator with linear variation range of 60 KHz~1.8 MHz at low THD of 2.1% are verified by both simulation and hardware tests.