| 释义 |
radio frequency
radio frequencyn. Abbr. RF1. The frequency of the waves transmitted by a specific radio station.2. A frequency within the range at which radio waves are transmitted, conventionally from 3 hertz to 300 megahertz, immediately below the range of microwave frequencies in the electromagnetic spectrum.radio frequency n 1. (Telecommunications) a. a frequency or band of frequencies that lie in the range 10 kilohertz to 300 000 megahertz and can be used for radio communications and broadcasting. Abbreviations: rf or RF See also frequency bandb. (as modifier): a radio-frequency amplifier. 2. (Broadcasting) the frequency transmitted by a particular radio station radio frequency A frequency at which radio waves can be transmitted, ranging from extremely low frequency (below 3000 hertz) to extremely high frequency (between 30 and 300 gigahertz).Thesaurus| Noun | 1. |  radio frequency - an electromagnetic wave frequency between audio and infraredstation - the frequency assigned to a broadcasting stationextremely low frequency, ELF - below 3 kilohertzvery low frequency, VLF - 3 to 30 kilohertzLF, low frequency - 30 to 300 kilohertzmedium frequency, MF - 300 to 3000 kilohertzhigh frequency, HF - 3 to 30 megahertzvery high frequency, VHF - 30 to 300 megahertzUHF, ultrahigh frequency - 300 to 3000 megahertzSHF, superhigh frequency - 3 to 30 gigahertzEHF, extremely high frequency - 30 to 300 gigahertzelectromagnetic spectrum - the entire frequency range of electromagnetic wavesfrequence, frequency, oftenness - the number of occurrences within a given time period; "the frequency of modulation was 40 cycles per second"; "the frequency of his seizures increased as he grew older" |
radio frequency
See also: Radio Frequencies (table)Radio Frequencies
Frequency
(kHz)
Name Abbr.
10–30 Very low VLF
30–300 Low LF
300–3,000 Medium MF
3,000–30,000 High HF
30,000–300,000 Very high VHF
300,000–3,000,000 Ultra high UHF
..... Click the link for more information. radio frequency, range of electromagnetic waves with a frequency or wavelength suitable for communication uses. Some of these waves serve as carriers of the lower-frequency audio waves; others are modulated by video or digital information. Short waves have relatively high frequencies; long waves have relatively low frequencies. Radio waves are identified by their frequencies, expressed in kilohertz (kHz), i.e., thousands of cycles per second, in megahertz (MHz), i.e., millions of cycles per second, or in gigahertz (GHz), i.e., billions of cycles per seconds. A range, or band, of radio frequencies is assigned to a broadcasting service by the nation in which it operates. In the United States, the Federal Communications CommissionFederal Communications Commission
(FCC), independent executive agency of the U.S. government established in 1934 to regulate interstate and foreign communications in the public interest.
..... Click the link for more information. is responsible for that task. Signals in the amplitude modulation (AM) broadcast band in the Americas have frequencies ranging from 530 to 1,700 kHz. Frequency modulation (FM) broadcast frequencies in most countries range from approximately 88 MHz to 108 MHz. Other frequencies are assigned to amateur (ham) radio, citizen band (CB) radio, television broadcasting, cellular telephones, global positioning systems, and other uses. Countries cooperate on on a worldwide basis through the International Telecommunication UnionInternational Telecommunication Union
(ITU), specialized agency of the United Nations, with headquarters at Geneva. It was created in 1934 as a result of the merging of the International Telegraph Union (est.
..... Click the link for more information. , which holds periodic conferences. See also the table entitled Radio FrequenciesRadio Frequencies
Frequency
(kHz)
Name Abbr.
10–30 Very low VLF
30–300 Low LF
300–3,000 Medium MF
3,000–30,000 High HF
30,000–300,000 Very high VHF
300,000–3,000,000 Ultra high UHF
..... Click the link for more information. for the classification of radio frequencies.radio frequency See radio waves.radio frequency[′rād·ē·ō ‚frē·kwən·sē] (electromagnetism) A frequency at which coherent electromagnetic radiation of energy is useful for communication purposes; roughly the range from 10 kilohertz to 100 gigahertz. Abbreviated rf. radio frequency
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 pacing" >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.3. relative frequency.radio frequency the range of frequencies of radiation" >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.AcronymsSeered flagradio frequency
Related to radio frequency: Radio Frequency Identification, Radio wavesWords related to radio frequencynoun an electromagnetic wave frequency between audio and infraredRelated Words- station
- extremely low frequency
- ELF
- very low frequency
- VLF
- LF
- low frequency
- medium frequency
- MF
- high frequency
- HF
- very high frequency
- VHF
- UHF
- ultrahigh frequency
- SHF
- superhigh frequency
- EHF
- extremely high frequency
- electromagnetic spectrum
- frequence
- frequency
- oftenness
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