Very high frequency (5877 bytes)
1: '''Very high frequency (VHF)''' is the [[radio frequency]] range from 30 [[megahertz|MHz]] (wavelength 10 ...
3: ...elevision]] broadcast (together with [[ultra high frequency|UHF]]). VHF is also commonly used for terrestria...
5: ...requency]] (UHF). UHF and VHF are the most common frequency bands for [[television]].
7: ...buildings and other less substantial objects than higher frequencies.
30: ...ir Traffic Control]] (AM), 121.5 MHz is emergency frequency

High frequency (1006 bytes)
1: '''High frequency (HF)''' [[radio frequency|radio frequencies]] are between 3 and 30 [[MHz]]....
11: *[[Maximum usable frequency]]
12: *[[Lowest usable frequency]]
13: *Frequency of operation within the HF range
18: *[[Very high frequency|VHF]], [[AM radio]], [[Radio propagation]]

Extremely high frequency (1085 bytes)
1: ...xtremely high frequency''' is the highest [[radio frequency]] [[band (radio)|band]]. '''EHF''' runs the [[ran...
3: ...o [[atmospheric]] [[attenuation]], making them of very little use over long [[distance]]s. Even over re...
7: ...SA, the band 38.6 - 40.0 GHz is used for licensed high-speed microwave data links, and the 60 GHz band c...

Ultra high frequency (5889 bytes)
1: :''This article is about the radio frequency. See also [[UHF (movie)]]''
3: ...[electromagnetic_spectrum]] for a full listing of frequency bands.
7: UHF and VHF are the most common frequency bands for [[television]]. Modern [[mobile phone]]...
13: ... However, this effect increases according to the frequency: UHF signals are generally more degraded by moist...
21: ...in advantage of UHF transmission is that its high frequency means it has a physically short wave. Since the ...

High frequency limit (1018 bytes)
1: The '''high frequency limit''' of hearing is the upper extent to which ...
3: ...his phenomenon by producing sounds at frequencies higher than those audible to humans but well within th...
4: ...standard CD sample rate of 44.1 kHz, set somewhat higher than the calculated [[Nyquist-Shannon]] rate of...

High-energy radio-frequency weapons (692 bytes)
1: ... Frequency''' weapons are weapons designed to use high intensity [[radio wave]]s to disrupt [[electronic...

Gary and Jerri-Ann Jacobs High Tech High Charter School (4037 bytes)
1: ...'''High Tech High''' (HTH)) is a public charter [[high school]] in [[San Diego, California]]. It is the ...
3: ...nature of the more common 1500–2000 student high schools.
7: High Tech High currently occupies a building on the former Navy ...
13: ...ave commented that the environment is more like a high tech company office than a traditional school; le...
17: ...igh School, [[San Carlos, California]]; New Urban High School, [[Clackamas, Oregon]]; Mirta Ramirez Comp...

High Technology High School (518 bytes)
1: '''High Technology High School''', or '''HTHS''', founded in [[1991]], is...
4: * [http://www.hths.mcvsd.org/ High Technology High School] (official web site)

Frequency (3973 bytes)
1: ...aves of various frequencies; the lower waves have higher frequencies than those above.]]
2: ... event occurs per unit [[time]]. To calculate the frequency, one fixes a time interval, counts the number of ...
4: ...ond]]. Other units that have been used to measure frequency include: cycles per second, [[rpm|revolutions per...
6: ...f the event (the [[period]]) and then compute the frequency as the reciprocal of this time:
11: ==Frequency of waves==

Frequency allocation (1617 bytes)
1: ...ments in most countries, in a process known as '''frequency allocation''' or '''spectrum allocation'''. Since...
3: ...forums and standards bodies work on standards for frequency allocation, including:
9: High-demand sections of the electromagnetic spectrum m...
12: ...ttp://www.ntia.doc.gov/osmhome/allochrt.html U.S. Frequency Allocation Chart] - Covering the range 3kHz-300GH...
13: ...pdf/%24FILE/spectallocation.pdf Canadian Table of Frequency Allocations] - From [[Industry Canada]]

Negative frequency (3630 bytes)
1: '''Negative frequency''' is the rate of [[clockwise]] rotation in [[pha...
13: and for a negative frequency, the phase, <math>\varphi</math> is decreasing wi...
15: ...be complex, since real signals have [[Hermitian]] frequency spectra (i.e. if the signal is real, the real par...
17: Here is an example of a signal having a negative frequency:
19: [[Image:Negative frequency.png|318px]]

Frequency duplex (161 bytes)
1: ...mitter]] and [[receiver]] operates at different [[frequency|frequencies]].

Sampling frequency (3137 bytes)
1: The '''sampling frequency''' or '''sampling rate''' defines the number of [...
2: The inverse of the sampling frequency is the '''sampling period''' or '''sampling time'...
4: The sampling frequency can only be applied to [[sampler]]s in which each...
8: ...annon sampling theorem]] states that the sampling frequency has to be twice the [[bandwidth]] of the signal b...
11: In some cases, it is desirable to have a sampling frequency more than twice the bandwidth so that a [[digital...

Recombinant frequency (4300 bytes)
1: ...] (or [[gene]]s) during [[meiosis]]. Recombinant frequency is a measure of [[genetic linkage]] and is used i...
5: ...diploid]] cell. In this example, the recombinant frequency is 50% since 2 of the 4 gametes were recombinant ...
7: The recombinant frequency will always be 50 percent when two genes are loca...
9: ...equency of 50%, linked genes have a recombination frequency that is less than 50%.
11: ... increased frequency of PL and pl and a decreased frequency of Pl and pL (see chart below).

Frequency converter (1562 bytes)
1: ...[[Alternating current | AC voltage]] of desired [[frequency]] and magnitude.
3: ...ctor switching device. The low-voltage (< 1000 V) frequency converters are manufactured in powers ranging fro...
5: ...ere the control accuracy requirements can be very high.

Angular frequency (1996 bytes)
1: ...y '''[[angular velocity]]'''. The term '''angular frequency vector''' <math>\vec{\omega}</math> is sometimes ...
3: In [[SI]] units, angular frequency is measured in [[radian|radians]] per [[second]],...
12: ''&omega;'' is the angular frequency or angular speed (measured in [[radian]]s per [[s...
16: ''f'' is the [[frequency]] (measured in [[hertz]])
22: ...ple of ordinary frequency. However, using angular frequency is often preferable in many applications, as it a...

Global Frequency (950 bytes)
1: '''Global Frequency''' is [[Warren Ellis]]'s exploration of "Rescue F...
5: ...reparing a [[Global Frequency (television)|Global Frequency]] television series for [[2005]] with [[Michelle ...

Frequency response (850 bytes)
1: ...imits quoted. As such it is not a measure that is very useful in terms of the quality of reproduction, o...

Frequency compensation (3739 bytes)
1: ...waves)|phase]] over a larger range of operating [[Frequency|frequencies]].
5: ...pected to be used for a wide variety of purposes, frequency compensation is essential.
7: ...s, existing high frequency poles are shifted even higher. Proper design can ensure there is only a sing...
11: ...ts drawbacks. In fact, most op-amps have so much frequency compensation that they might be said to be ''over...
13: ...cal frequencies, negative feedback is preserved. Frequency compensation might be accomplished by adding a ca...

Frequency reference (410 bytes)
1: ...o electrical ones that emit a signal of a certain frequency.
3: Among the most stable frequency references in the world are [[caesium]]-based [[a...

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