In the paper, a programmable phase-locked loop (PLL) based ISM band fractional-N frequency synthesizer, commonly used in wireless communication system, is presented. The third order error-feedback Delta-Sigma modulator and high linearity offset phase frequency detector (PFD)/ Charge Pump (CP) are adopted to reduce close-in phase noise due to ∆Σ quantization noise folding. Automatic calibration ...

1. Definition. A PLL is a feedback system that includes a VCO, phase detector, and low pass filter within its loop. Its purpose is to force the VCO to replicate and track the frequency and phase at the input when in lock. The PLL is a control system allowing one oscillator to track with another. It is possible to have a phase offset between input and output, but when locked, the frequencies mus...

A clock with low phase-noise/jitter is a prerequisite for high-performance ADCs, wireline and optical data links and radio transceivers. This paper presents a 2.2GHz clock-generation PLL. It uses a phase-detector/charge-pump (PD/CP) that sub-samples the VCO output with the reference clock. The PLL does not need frequency divider in locked state and achieves a low in-band phase noise values at l...

The ability to detect surfaces within confocal microscope images is important for the interpretation of such data. Most detectors are gradient-based, and so are sensitive to noise, and fail to detect some feature types that are important in confocal microscopy. The local energy feature detector developed by Morrone and Owens marks locations where there is congruence of phase in the Fourier comp...

Certain problems associated with reliable digital wireless communication over a frequency-flat slow Rayleigh fading channel are treated, when the transmitted signal is modulated using continuous phase modulation (CPM) due to the desirable properties of CPM. The primary focus of attention is on detection strategies, and the thesis proposes iterative detection algorithms for CPM signals transmitt...

There are three different loop detectors used to detect present and absent vehicles.’ One of them is known as self-tuning detector. This type of detector utilizes both pavement loops as part of a parallel resonant tank circuit and a closed-loop feedback circuit. It automatically adjusts a voltage-tuned oscillator to a predetermined frequency relative to the resonant frequency of the tank.’ A ch...

Wireless communication is a fast-growing industry and recent developments focus on improving certain aspects of the area reducing power consumption while maintaining frequency operation. Phase Locked Loop (PLL) an integral part circuits which operate at very high frequencies. Frequency Detector (PFD) first block PLL key in determining computational capacity PLL. The PFD has to be reduced minimi...

Pitch is a perceptual correlate of periodicity. Sounds with distinct spectra can elicit the same pitch. Despite the importance of pitch perception, understanding the cellular mechanism of pitch perception is still a major challenge and a mechanistic model of pitch is lacking. A multi-stage neuronal network model is developed for pitch frequency estimation using biophysically-based, high-resolut...