This paper gives experimental proof of an intriguing physical effect: periodic on–off switching of MOS transistors in a CMOS ring oscillator reduces their intrinsic 1=f noise and hence the oscillator’s close-in phase noise. More specifically, it is shown that the 1=f phase noise is dependent on the gate-source voltage of the MOS transistors in the off state. Measurement results, corrected for w...

In the present paper, parameterized Spice models are developed for the phase noise simulation. It is accomplished by a standard frequency and noise analysis for obtaining the noise factor using the noise sources, incorporated in the library elements. Based on the Leeson model, the single-sideband phase noise is investigated. An approach is developed to phase noise reduction in oscillator circui...

We report an adaptive weighted channel equalizer (AWCE) for orthogonal frequency division multiplexing (OFDM) and study its performance for long-haul coherent optical OFDM (CO-OFDM) transmission systems. This equalizer updates the equalization parameters on a symbol-by-symbol basis thus can track slight drifts of the optical channel. This is suitable to combat polarization mode dispersion (PMD)...