Op-Amp Based LC Oscillator with Minimum Components for Wireless Communications

This paper presents a new circuit of op-amp based LC oscillator design for wireless communications. This LC oscillator can be classified as a harmonic oscillator. Unlike Hartley, Colpitis and Clapp oscillators, the resonant tank circuit of the proposed op-amp based LC oscillator is composed of only two components --- single-inductor and single-capacitor, in parallel connection. Also, the LC oscillator does not use resistor components. The aim of this paper is to provide a low cost solution for sinusoidal oscillator design, particularly in low power mobile applications, where the power amplifier stage can be eliminated if the RF oscillator has enough output current and output voltage capabilities to supply the antenna load. On the other hand, the digital modulator is also integrated with the RF oscillator. The proposed op-amp based LC oscillator is analyzed and discussed using PSPICE simulation results. To verify the concept, experimental results are given. It can be observed that the simulation results are in line with the experimental results.