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.
Miller-Keane Encyclopedia and Dictionary of Medicine, Nursing, and Allied Health, Seventh Edition. © 2003 by Saunders, an imprint of Elsevier, Inc. All rights reserved.

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.
Segen's Medical Dictionary. © 2012 Farlex, Inc. All rights reserved.
References in periodicals archive ?
The second step is assignment, in which the government decides who gets to use what parts of the radio spectrum. The assignment, which is expressed as a license, generally specifies a particular frequency band, the geographic region, and the level of power that can be used for the radio signal.
Radio spectrum also generates big bucks for governments.
International and national management of the radio spectrum was first introduced in response to the sinking of the Titanic in 1912, where failures in radio communications led to the needless deaths of 1,502 people.
Americans will talk for trillions of minutes and send trillions of text messages through wireless radio spectrums in 2012, generating revenue of $202 billion.
The goal is to make better use of a huge swath of the radio spectrum now controlled by federal agencies.
"While spectrum management has always been important, the complexity of the task has been compounded by the proliferation of both traditional and entirely new radio spectrum frequency-using services in recent years," Sibal said.
Two years ago, the Federal Communications Commission reserved a 10-megahertz block of radio spectrum for public-safety use.
Staff monitoring the use of the radio spectrum have located a number of sources who are violating the conditions of their frequency licence including the permitted transmit power.
TELECOMWORLDWIRE-14 May 2009-Inmarsat PLC selected to operate S-band radio spectrum in Europe(C)1994-2009 M2 COMMUNICATIONS LTD http://www.m2.com
By 2010, the Army expects to have over 1,500 Soldiers trained in the art of "blinding and deafening" America's enemies by wielding the radio spectrum as a weapon.
US wireless technology firm Qualcomm has acquired radio spectrum in Britain known as L-band and is looking for a partner to launch services such as mobile television.
The readers support various radio spectrum options including low frequency (LF), high frequency (HF), ultra high frequency (UHF) passive and active.