Análise Comparativa de Osciladores Senoidais das Topologias Pierce, Colpitts e Clapp Empregando Modelo de Sensor a Onda Acústica de Superfície na Malha de Realimentação

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Abstract

This work presents a comparative analysis, through computer simulations, of sinusoidal oscillators
of the Pierce, Colpitts and Clapp topologies employing a surface acoustic wave sensor model. To
carry out the simulations, sinusoidal oscillators with a common emitter amplifier and an oscillationfrequency of 117 MHz and the surface acoustic wave sensor model based on the model of a
piezoelectric crystal were chosen. The output data of the simulations were the amplitude and the
oscillation frequency of the output voltage of the oscillators with the sensor model. From the
comparative analysis of the oscillation frequency of each oscillator, percentage errors of less than
1% were found, which enables the use of the oscillators designed for the VHF frequency range.
From the comparative analysis of the output voltage amplitude of each oscillator, it was found that
the amplitude of the Clapp oscillator was 20% greater than the amplitude of the Colpitts oscillator
and 61.54% greater than the amplitude of the Pierce oscillator. With this result, it appears that the
Clapp oscillator is the most suitable to be used in this frequency range with the surface acoustic
wave sensor for the measurement of large samples of disturbances. On the other hand, Pierce and
Colpitts oscillators would be more suitable for measurements of small perturbation samples, since
their topologies have a smaller number of components, reducing the manufacturing cost.