radio frequency

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frequency

 [fre´kwen-se]
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 ?
Governments provide radio spectrum for commercial uses in two basic steps.
These three-year awards continue NSF's ongoing investment in radio spectrum research, which over the past five years has supported more than 140 awards through an investment of over $60 million.
TRA will continue to monitor the use of the radio spectrum and where necessary will initiate legal action," he said.
Excited by the prospects of a possible cash cow, the mobile and broadcast industries are in a hurry to launch commercial services, but it is not clear which technology is the best or what radio spectrum is available in the European region.
Since 1959, the agency has tried to protect scientists by setting aside a few small slivers of the radio spectrum.
It wasn't until the late 1920s that the Federal Radio Commission, predecessor to the FCC, was established to oversee the radio spectrum, impose broadcasting standards, and issue broadcasting licenses.
Open Competition: Performing research work on the topic: Research on the conversion of the radio spectrum in the band 301-470 MHz radio, working conditions of the joint use of the radio spectrum radio-electronic means of broadband wireless access with radio-electronic means for military purposes
JOSEPH VARGHESE DOHA THE Supreme Council of Information and Communication Technology (ictQatar) on Monday issued the country's first Radio Spectrum Policy.
The decision does not force the countries to open up 800 MHz to such services but the EU executive notes that it is considering such a proposal in its forthcoming radio spectrum policy programme for 2011-2015, to be presented by the summer.
TELECOMWORLDWIRE-25 February 2008-MLL Telecom wins radio spectrum licences in Ofcom auction(C)1994-2008 M2 COMMUNICATIONS LTD http://www.
First, the company had to get international permission to use a special band on the radio spectrum.