Designing the Ring-Type Voltage Controlled Oscillator
A voltage controlled oscillator (VOC), in fact, is a generator of adjustable frequency. A VOC is used as a key part in the phase lock ring, which is a system that generates a sustained oscillating signal. Since the digital electronics industry needs a growing increase of performance in speed, it is necessary that the VOCs generate the signals in higher frequencies. But, as the frequency increases, the VOC phase noise decreases. Even though there are two main types of VOCs i.e. ring and capacitive-inductive types, in this research, the ring oscillator is designed and simulated using the Dual-gate transistors. The results showed that, compared to MOSFET transistors, frequencies could be generated using the dual-gate transistors. Then, various signals were generated using the op-amp and frequency divider and also using the ring oscillator. Finally, three outputs were weighted and summed and it was shown that oscillations with three times of frequency could be generated using the weighted sum of the phase shift oscillator output.