nounA state of nervous restlessness or agitation. fidget (often used in plural), jump (used in plural), shiver1 (used in plural), tremble (often used in plural). Informal all-overs, shake (used in plural). Slang heebie-jeebies, jim-jams, willies. See calm/agitation, fear/courage. Aviation Dictionary: jitterTopHome > Library > Cars & Vehicles > Aviation Dictionary .borderbottom{ border-bottom: solid .01em gray; margin-top: 1.5em; margin-bottom: 1.5em; }.bordertop{ border-top: solid .01em gray; margin-top: 1.5em; margin-bottom: 1.5em; }.bordertopbottom{ border-bottom: solid .01em gray; border-top: solid .01em gray; margin-top: 1.5em; margin-bottom: 1.5em; }.bordertopbottomright{ border-bottom: solid .01em gray; border-top: solid .01em gray; border-right: solid .01em gray; margin-top: 1.5em; margin-bottom: 1.5em; }.borderrightbottom{ border-bottom: solid .01em gray; border-right: solid .01em gray; margin-top: 1.5em; margin-bottom: 1.5em; }.borderleftrightbottom{ border-bottom: solid .01em gray; border-left: solid .01em gray; border-right: solid .01em gray; margin-top: 1.5em; margin-bottom: 1.5em; }.borderleftright{ border-left: solid .01em gray; border-right: solid .01em gray; margin-top: 1.5em; margin-bottom: 1.5em; }.borderright{ border-right: solid .01em gray; margin-top: 1.5em; margin-bottom: 1.5em; }.borderlefttopbottom{ border-bottom: solid .01em gray; border-left: solid .01em gray; border-top: solid .01em gray; margin-top: 1.5em; margin-bottom: 1.5em; }.borderall{ border-bottom: solid .01em gray; border-top: solid .01em gray; border-left: solid .01em gray; border-right: solid .01em gray; } i. An ECCM (electronic counter-countermeasure) technique in which the radar PRF (pulse repetition frequency) is made to vary in a random manner.ii. The instability of the signal or trace of a cathode-ray tube.iii. Small rapid variations in a waveform caused by deliberate or accidental electrical or mechanical disturbances or to changes in the supply voltages, in the characteristic of components, etc. document.write('') Wikipedia: JitterTopHome > Library > Miscellaneous > Wikipedia For other meanings of this word, see Jitter (disambiguation).This article needs additional citations for verification.Please help improve this article by adding reliable references. Unsourced material may be challenged and removed. (March 2009)Jitter in technical terms is the deviation in or displacement of some aspect of the pulses in a high-frequency digital signal. As the name suggests, jitter can be thought of as shaky pulses. The deviation can be in terms of amplitude, phase timing, or the width of the signal pulse. Another definition is that it is "the period frequency displacement of the signal from its ideal location." Among the causes of jitter are electromagnetic interference (EMI) and crosstalk with other signals. Jitter can cause a display monitor to flicker; affect the ability of the processor in a personal computer to perform as intended; introduce clicks or other undesired effects in audio signals, and loss of transmitted data between network devices. The amount of allowable jitter depends greatly on the application.

Jitter is the time variation of a periodic signal in electronics and telecommunications, often in relation to a reference clock source. Jitter may be observed in characteristics such as the frequency of successive pulses, the signal amplitude, or phase of periodic signals. Jitter is a significant, and usually undesired, factor in the design of almost all communications links (e.g., USB, PCI-e, SATA, OC-48). In clock recovery applications it is called timing jitter.

Jitter can be quantified in the same terms as all time-varying signals, e.g., RMS, or peak-to-peak displacement. Also like other time-varying signals, jitter can be expressed in terms of spectral density (frequency content).

Jitter period is the interval between two times of maximum effect (or minimum effect) of a signal characteristic that varies regularly with time. Jitter frequency, the more commonly quoted figure, is its inverse. Generally, very low jitter frequency is not of interest in designing systems, and the low-frequency cutoff for jitter is typically specified at 1 Hz.

In conversion between digital and analog signals, the sampling frequency is normally assumed to be constant. Samples should be converted at regular intervals. If there is jitter present on the clock signal to the analog-to-digital converter or a digital-to-analog converter then the instantaneous signal error introduced will be proportional to the slew rate of the desired signal and the absolute value of the clock error. Various effects[specify] can come about depending on the pattern of the jitter in relation to the signal. In some conditions, less than a nanosecond of jitter can reduce the effective bit resolution of a converter with a Nyquist frequency of 22 kHz to 14 bits[citation needed].

This is a consideration in high-frequency signal conversion, or where the clock signal is especially prone to interference.

In the context of computer networks, the term jitter is often used as a measure of the variability over time of the packet latency across a network. A network with constant latency has no variation (or jitter). Packet jitter is expressed as an average of the deviation from the network mean latency. However, for this use, the term is imprecise. The standards-based term is packet delay variation (PDV). PDV is an important quality of service factor in assessment of network performance.

In the context of digital audio extraction from Compact Discs, seek jitter causes extracted audio samples to be doubled-up or skipped entirely if the Compact Disc drive re-seeks. The problem occurs because the Red Book (audio CD standard) does not require block-accurate addressing during seeking. As a result, the extraction process may restart a few samples early or late, resulting in doubled or omitted samples. These glitches often sound like tiny repeating clicks during playback. A successful approach to correction in software involves performing overlapping reads and fitting the data to find overlaps at the edges. Most extraction programs perform seek jitter correction. CD manufacturers avoid seek jitter by extracting the entire disc in one continuous read operation using special CD drive models at slower speeds so the drive does not re-seek.

A jitter meter is a testing instrument for measuring clock jitter values, and is used in manufacturing DVD and CD-ROM discs.

Due to additional sector level addressing added in the Yellow Book (CD standard), CD-ROM data discs are not subject to seek jitter.