A novel noise-shifting differential Colpitts VCO is presented. It uses current switching to lower phase noise by cyclostationary noise alignment and improve the start-up condition. A design strategy is also devised to enhance the phase noise performance of quadrature coupled oscillators. Two integrated VCOs are presented as design examples.

Recently, the small size and the low power are required as the demand of the wireless communication application field increases. Because there are various problems that it is generated as the size and power consumption become smaller, many efforts are necessary in order to solve it. In the case of an oscillator, 1/f noise is increased as the size of chip becomes smaller. Therefore this affects ...

The authors report all the possible four-impedance settings that yield a valid second-order two-stage Colpitts oscillator. These settings are obtained following an exhaustive search conducted on two possible structures of the oscillator modelled through two-port network transmission parameters. Only valid second-order cases with a maximum of three reactive elements are reported. Experimental an...

In this work a new approach to stability analysis is applied to nonlinear oscillators. Based on the use of local metrics properties of curvature and torsion resulting from Differential Geometry and while considering trajectory curves as plane or space curves, these properties directly provide their slow manifold analytical equation and its stable and unstable parts. Van der Pol and Colpitts mod...

This paper discusses an analytical description of low frequency upconversion in LC oscillators. We show that upconversion into phase noise can be substantially reduced by modification of circuit topology. The theoretical discussion is supported by measurements of a 100 MHz BJT Colpitts model oscillator.

Abstract: In this paper, a microwave chaotic oscillator with symmetric active load is presented. Compared to the classical Differential bipolar Chaotic Colpitts Oscillator (DCCO) produces anti-phase dual output carriers with intense chaotic behaviour, better linearity and very good encryption capabilities. Advanced Design System (ADS) 2008 Update 1 simulations performed up to 30 GHz, which demo...

A single-trim, highly accurate Colpitts-based frequency reference is presented. Our analysis shows that the Colpitts-topology outperforms cross-coupled LC -topology in terms of temperature stability. Measurements on prototypes a 0.13- ...

In this work we present a detailed study of the phase noise of subharmonic injection locked oscillators (s-ILOs). A new simple and efficient model has been presented for accurately predicting the phase noise of a microwave s-ILO. The validity of the analytical technique is verified with measurement results obtained from a 5-GHz fully differential Colpitts-based s-ILO. The results showed that a ...