Recent Trends in LC Voltage Controlled Oscillator to Achieve Low Phase Noise: A literature survey

The Voltage Controlled Oscillator is the most essential part of the transceivers that deals with generating a system frequency in the RF range for most of the wireless Devices. LC voltage Controlled Oscillator plays essential role in the many applications of RF frequency band – ISM frequency band (Industrial, Scientific, Medical) like Zigbee, Bluetooth, front-end RF transceiver, - IEEE 802.11a/b/g, - IEEE 802.15.4, etc. The performance and accuracy of these application designs depends upon the features and development methods of the Oscillator. As requirement to fulfil accuracy and power constrains, new techniques have been presented to improve the features like phase noise, FOM, tail current and low power. In this era, we have different methods to improve features of VCO to get the better results. Still research is going on to achieve more accurate results. So, questions may arise in researches’ mind about selection of the technique to improve the performance for required application. The selection of the proper technique involves improvement of particular feature and which improves overall performance of the system. This is the main motive to write a comprehensive survey of Voltage controlled Oscillator from forgoing to contemporary. In this paper, Details of all the techniques to improve Phase noise in the RF – ISM frequency band with merits - demerits including low power and FOM is presented. In this paper comparative analysis is also given to find the features in this field. The paper is concluded with the survey, which serves as reference for the researchers in the field of RF – ISM Frequency band LC Voltage controlled oscillator.