radio frequency

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1. the number of occurrences of a periodic or recurrent process in a unit of time, such as the number of electrical cycles per second measured in hertz. In cardiac pacing terminology, frequency is expressed by the formula: frequency = ½ × pulse width.
2. the number of occurrences of a particular event or the number of members of a population or statistical sample falling in a particular class.
radio frequency the range of frequencies of electromagnetic radiation between 10 kilohertz and 100 gigahertz, used for radio communication.
relative frequency the ratio of the number of occurrences of a specified phenomenon in a population to the total size of the population.
urinary frequency urination at short intervals without increase in daily volume of urinary output, due to reduced bladder capacity or cystitis.

radio frequency

An MRI term for an electromagnetic wave with a frequency in the same range as that used for transmitting radio and television signals. The RF pulses used in MRI are usually in the 1–100 megahertz range, which cause heating of a structure or tissue due to RF pulse absorption.
References in periodicals archive ?
Except for the radio frequencies someone else is operating on at that precise moment, the entire electromagnetic spectrum is available for use 24/7.
Natural resources such as oil, coal and precious metals are limited or finite and are in high demand; similarly, radio frequencies from the electromagnetic spectrum are also in high demand.
RF surveys are out-of-date before they are finished and consumers cannot be expected to continuously change radio frequencies because their cordless phone is interfering with their baby monitor or TiVo(R).

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