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

摘要

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.