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Radio frequency ( RF) is the oscillation rate of an alternating electric current or voltage or of a magnetic, electric or electromagnetic field or mechanical system in the frequency [ 1] range from around 20 kHz to around 300 GHz. This is roughly between the upper limit of audio frequencies and the lower limit of infrared frequencies, and also ...
The radio spectrum is the part of the electromagnetic spectrum with frequencies from 3 Hz to 3,000 GHz (3 THz ). Electromagnetic waves in this frequency range, called radio waves, are widely used in modern technology, particularly in telecommunication. To prevent interference between different users, the generation and transmission of radio ...
Pulsed radiofrequency is the technique whereby radio frequency (RF) oscillations are gated at a rate of pulses (cycles) per second (one cycle per second is known as a hertz (Hz)). Radio frequency energies occupy 1.0 × 104 Hz to 3.0 × 1011 Hz of the electromagnetic spectrum. Radio frequency electromagnetic energy is routinely produced by RF ...
A chirp is a signal in which the frequency increases ( up-chirp) or decreases ( down-chirp) with time. In some sources, the term chirp is used interchangeably with sweep signal. [1] It is commonly applied to sonar, radar, and laser systems, and to other applications, such as in spread-spectrum communications (see chirp spread spectrum ).
This gives a net polarization that is parallel to the external field. Application of an RF pulse can tip this net polarization vector sideways (with, i.e., a so-called 90° pulse), or even reverse it (with a so-called 180° pulse). The protons will come into phase with the RF pulse and therefore each other. [citation needed]
E-AC3. v. t. e. Dolby Digital Plus, also known as Enhanced AC-3 (and commonly abbreviated as DDP, DD+, E-AC-3 or EC-3 ), is a digital audio compression scheme developed by Dolby Labs for the transport and storage of multi-channel digital audio. It is a successor to Dolby Digital (AC-3), and has a number of improvements over that codec ...
A direct solution to the pulse design problem was independently proposed by Shinnar and Le Roux based on a discrete approximation to the spin domain version of the Bloch equations. Theory [ edit ] The SLR algorithm simplifies the solution of the Bloch equations to the design of two polynomials, which can be solved using well-known digital ...
Pulse-repetition frequency (PRF) is the number of times a pulsed activity occurs every second. This is similar to cycle per secondused to describe other types of waveforms. PRF is inversely proportional to time period T{\displaystyle \mathrm {T} }which is the property of a pulsed wave. T=1PRF{\displaystyle \mathrm {T} ={\frac {1}{\text{PRF}}}}