Gain - Revision history

TimVK4YEH: /* Gain compared to a half wave dipole - dBD */

2010-11-22T09:17:52Z

Gain compared to a half wave dipole - dBD

← Older revision		Revision as of 02:17, 22 November 2010
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	''Pe'' = 3, ''Pi'' = 1		''Pe'' = 3, ''Pi'' = 1

	<math> 10 \times \log \left( \frac {3}{1} \right) = 4.77\mbox{dBD} </math>		<math>10\times\log\left(\frac {3}{1}\right) = 4.77\mbox{dBD} </math>

	===Gain compared to an isotropic radiator = dBi ===		===Gain compared to an isotropic radiator = dBi ===

2009-07-21T09:41:09Z

antenna comparison table

← Older revision		Revision as of 02:41, 21 July 2009
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	hence, <math> dBi = dBD + 2.15 </math>		hence, <math> dBi = dBD + 2.15 </math>

			===Comparative gain of various antenna types===

			{\| width="750" border="1" cellpadding="6"
			\| Antenna Type
			\| dB gain over isotropic radiator
			\| dB gain over half-wave dipole
			\|-
			\| Isoptropic radiator
			\| 0
			\| -2.1
			\|-
			\| Ground plane
			\| +0.3
			\| -1.8
			\|-
			\| half-wave dipole
			\| +2.1
			\| 0
			\|-
			\| 5/8 wave dipole
			\| +3.3
			\| +1.2
			\|-
			\| Quad loop single element
			\| +4.1
			\| +2
			\|-
			\| 2 element yagi
			\| +7.1
			\| +5
			\|-
			\| 3 element yagi
			\| +10.1
			\| +8
			\|-
			\| 4 element yagi
			\| +12.1
			\| +10
			\|-
			\| 2 element quad
			\| +9.1
			\| +7
			\|-
			\| 3 element quad
			\| +12.1
			\| +10
			\|-
			\| 4 element quad
			\| +14.1
			\| +12
			\|}


			Adapted from Orr WL (W6SAI) and Cowan SD (W2LX), 1986, the Radio Amateur Antenna Handbook

	===dBo Optical Gain===		===dBo Optical Gain===

2009-07-21T04:15:18Z

optical gain

← Older revision		Revision as of 21:15, 20 July 2009
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	<math> 10 \times \log \left( \frac {3}{1} \right) = 4.77\mbox{dBD} </math>		<math> 10 \times \log \left( \frac {3}{1} \right) = 4.77\mbox{dBD} </math>

	===Gain compared to an isotropic ~~readiator~~ = dBi ===		===Gain compared to an isotropic radiator = dBi ===

	An isotropic radiator is a theoretical "point source" antenna that radiates the same amount of energy in all directions. Although an isotropic antenna cannot be constructed, it is sometimes useful to compare actual antennas to it.		An isotropic radiator is a theoretical "point source" antenna that radiates the same amount of energy in all directions. Although an isotropic antenna cannot be constructed, it is sometimes useful to compare actual antennas to it.
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	hence, <math> dBi = dBD + 2.15 </math>		hence, <math> dBi = dBD + 2.15 </math>

			===dBo Optical Gain===

			dBO is an unofficial term used by some amateurs working with transmission of data using light. It refers to the apparent gain of an optical system compared to a point source of light.


	{{electronics}}		{{electronics}}

2009-07-21T04:09:45Z

decibels

← Older revision		Revision as of 21:09, 20 July 2009
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	=== Gain compared to a half wave dipole - dBD===		=== Gain compared to a half wave dipole - dBD===

	The gain of an antenna is the relative increase in radiation at the maximum point expressed as a value in [[Decibels \| dB ]] above a standard. The standard to which other antennas are compared is usually a ½-wavelength dipole. The standard antenna is given a reference gain of 0dBD (zero decibel referenced to dipole). This comes from:		The gain of an antenna is the relative increase in radiation at the maximum point expressed as a value in [[Decibels \| decibels (dB) ]] above a standard. The standard to which other antennas are compared is usually a ½-wavelength dipole. The standard antenna is given a reference gain of 0dBD (zero decibel referenced to dipole). This comes from:

	<math> \mbox{gain} = 10 \times \log \left( \frac {Pe}{Pi} \right) </math>		<math> \mbox{gain} = 10 \times \log \left( \frac {Pe}{Pi} \right) </math>

2009-04-09T01:17:05Z

Comparison of dBD and dBi

2009-04-04T23:14:08Z

← Older revision		Revision as of 16:14, 4 April 2009
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	Related wiki pages [[Antennas]], [[Antenna Design]], [[Radiated Power Measurement]], [[SWR]]		Related wiki pages [[Antennas]], [[Antenna Design]], [[Decibels]], [[Radiated Power Measurement]], [[SWR]]

	==What is Gain?==		==What is Gain?==
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	=== Gain compared to a half wave dipole - dBD===		=== Gain compared to a half wave dipole - dBD===

	The gain of an antenna is the relative increase in radiation at the maximum point expressed as a value in dB above a standard. The standard to which other antennas are compared is usually a ½-wavelength dipole. The standard antenna is given a reference gain of 0dBD (zero decibel referenced to dipole). This comes from:		The gain of an antenna is the relative increase in radiation at the maximum point expressed as a value in [[Decibels \| dB ]] above a standard. The standard to which other antennas are compared is usually a ½-wavelength dipole. The standard antenna is given a reference gain of 0dBD (zero decibel referenced to dipole). This comes from:

	<math> \mbox{gain} = 10 \times \log \left( \frac {Pe}{Pi} \right) </math>		<math> \mbox{gain} = 10 \times \log \left( \frac {Pe}{Pi} \right) </math>

2009-04-04T21:35:52Z

← Older revision		Revision as of 14:35, 4 April 2009
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	Related wiki pages [[Antennas]], [[Antenna Design]], [[SWR]]		Related wiki pages [[Antennas]], [[Antenna Design]], [[Radiated Power Measurement]], [[SWR]]

	==What is Gain?==		==What is Gain?==

2008-08-22T09:33:31Z

← Older revision		Revision as of 02:33, 22 August 2008
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	Related wiki pages [[Antennas]], [[Antenna Design]]		Related wiki pages [[Antennas]], [[Antenna Design]], [[SWR]]

	==What is Gain?==		==What is Gain?==

2008-08-10T07:22:49Z

Gain compared to a half wave dipole - dBD

← Older revision		Revision as of 00:22, 10 August 2008
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	An antenna with the effective radiated power of three times the input power would therefore have a gain of:		An antenna with the effective radiated power of three times the input power would therefore have a gain of:

	Pe = 3, Pi = 1		''Pe'' = 3, ''Pi'' = 1

	<math> 10 \times \log \left( \frac {3}{1} \right) = 4.77\mbox{dBD} </math>		<math> 10 \times \log \left( \frac {3}{1} \right) = 4.77\mbox{dBD} </math>

2008-08-07T10:19:01Z

internal link

← Older revision		Revision as of 03:19, 7 August 2008
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	Related wiki pages [[Antennas]]		Related wiki pages [[Antennas]], [[Antenna Design]]

	==What is Gain?==		==What is Gain?==