Wandering spur suppression in a 4.9-GHz fractional-N frequency synthesizer

Fractional-N frequency synthesizers that use a digital Δ-Σ modulator (DDSM) to control the feedback divider can exhibit spurious tones that move about in the frequency domain; these are known colloquially as ``walking'' or wandering spurs. Building upon a theoretical explanation of the origin of wandering spurs, this article presents two methods to suppress them. It describes a 4.9-GHz 180-nm SiGe BiCMOS charge-pump phase-locked loop (CP-PLL) fractional-N frequency synthesizer platform with a divider controller that can function as: 1) a standard MASH 1-1-1; 2) a MASH 1-1-1 with high-amplitude dither; and 3) a MASH 1-1-1 with a modified third stage. Measurements confirm the effectiveness of the wandering spur suppression strategies

Analysis of Wandering Spur Patterns in a Fractional-N Frequency Synthesizer with a MASH-Based Divider Controller

The Multi-stAge noise SHaping Digital Delta-Sigma Modulator (MASH DDSM), which is commonly used as a divider controller in a fractional- N frequency synthesizer, can produce a time-varying periodic pattern of tones in the output spectrum of the synthesizer; these are known as wandering spurs. In this work, a detailed analysis of the cause of wandering spur patterns in a MASH 1-1-1 DDSM-based fractional- N frequency synthesizer, supported by experimental measurements, is presented

The Music Sound

A guide for music: compositions, events, forms, genres, groups, history, industry, instruments, language, live music, musicians, songs, musicology, techniques, terminology , theory, music video. Music is a human activity which involves structured and audible sounds, which is used for artistic or aesthetic, entertainment, or ceremonial purposes. The traditional or classical European aspects of music often listed are those elements given primacy in European-influenced classical music: melody, harmony, rhythm, tone color/timbre, and form. A more comprehensive list is given by stating the aspects of sound: pitch, timbre, loudness, and duration. Common terms used to discuss particular pieces include melody, which is a succession of notes heard as some sort of unit; chord, which is a simultaneity of notes heard as some sort of unit; chord progression, which is a succession of chords (simultaneity succession); harmony, which is the relationship between two or more pitches; counterpoint, which is the simultaneity and organization of different melodies; and rhythm, which is the organization of the durational aspects of music