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Topic: Antenna gain

Related Topics

List of antenna terms

Aperture (antenna)

Effective Radiated Power

Cassegrain antenna

Feedhorn

Beamwidth

Glossary of Telecommunication Terms

Parabolic reflector

	Antenna (radio) - Wikipedia, the free encyclopedia (Site not responding. Last check: 2007-11-07)
		Complex impedance of an antenna is related to the electrical length of the antenna at the wavelength in use.
		Gain is measured by comparing an antenna to a model antenna, typically the isotropic antenna which radiates equally in all directions.
		The Phased array antenna is a group of independently fed active elements in which the relative phases of the respective signals feeding the elements are varied in such a way that the effective radiation pattern of the array is reinforced in a desired direction and suppressed in undesired directions.
	en.wikipedia.org /wiki/Antenna_(electronics) (2853 words)

	Antenna gain - Wikipedia, the free encyclopedia
		Antenna gain is the measurement of an antennas ability to amplify the incoming microwave signals in a particular direction, compared with the sensitivity of an isotropic antenna in any direction, or a dipole antenna in the equatorial direction.
		For dish-type antennas, gain is proportional to the aperture (reflective area) and surface accuracy of the antenna, as well as the frequency being transmitted/received.
		Gain, expressed in decibels, or dB, is primarily a function of antenna capture area or aperture: the larger the antenna aperture, the higher the antenna gain.
	en.wikipedia.org /wiki/Antenna_gain (463 words)

	Antenna Tutorial on Gain and Beamwidth From ATI Space and Communications Training Courses (Site not responding. Last check: 2007-11-07)
		Consequently, the gain increases as the wavelength decreases or the frequency increases.
		, the gain is 27,000 or 44.3 dB.
		The antenna is illuminated by an array of 146 Potter horns.
	www.aticourses.com /antennas_tutorial.htm (4441 words)

	How To Become An Antenna Guru
		The equivalent circuit is a simple series RLC circuit as shown in figure 1a where the inductance represents the inductance of the conductors, the capacitor is the capacitance between the conductors and the resistance represents the energy lost to radiation.
		If the antenna is electrically large, the pattern will have more structure, that is more peaks and nulls and the more directive will be the main lobe as shown in figure 4 for a dipole antenna that is 10.25 wavelengths long.
		The beamwidth of an antenna is a measure of the directivity of an antenna and is usually defined by the angles where the pattern drops to one half of its peak value or known as the 3db points.
	www.borg.com /~warrend/guru.html (4657 words)

	Antennas
		Antennas are also used in "receive mode" to collect radiation from "free space" and deliver the energy contained in the propagating wave to the feeder and receiver.
		The biconical antenna, and its derivatives, the broad-banded Yagi, the bow-tie antenna and the phantom conical antenna (which doesn't have a complete conical surface, but just conically disposed rod elements), is a good method of broad-banding a dipole type of antenna.
		In a reflector-aperture antenna fed from the front by a sub-reflector and/or a feed, the far field radiation pattern can be calculated from the Fourier Transform of the field distribution across the aperture, accounting as well for phase variations across the illuminated area.
	www.ee.surrey.ac.uk /Personal/D.Jefferies/antennas.html (9048 words)

	Radiall-Larsen Antenna Technologies : Technical Reference : Basic Antenna Concepts
		Radiation or antenna pattern describes the relative strength of the radiated field in various directions from the antenna at a constant distance.
		Beamwidth Increased: The aperture of the radiating element is modified and the gain of the antenna is decreased.
		Omni-ceiling mount antennas are used for the propagation of data in an in-building environment.
	www.radialllarsen.com /technicalreference_basicantennaconcepts.htm (2731 words)

	AlternativeWireless.com Cell Phone Antennas Power Boosters Cellular Amplifiers Phone Adapters Connectors
		When selecting a mobile antenna, there are a number of factors that significantly affect the ultimate performance of the cell antenna.
		Gain requirements, electrical type, ground plane availability mounting style and placement, coaxial type and loss ratings, physical size, appearance, and surrounding environment are all issues that must be addressed to ensure the maximum performance from a mobile antenna installation.
		A 3 dBd gain antenna is the compromise and a great all around solution in suburban and general settings.
	www.antennazone.com (743 words)

	Marc's Technical Pages: Antenna Gain Explained
		Antenna Gain: The relative increase in radiation at the maximum point expressed as a value in dB above a standard, in this case the basic antenna, a ½-wavelength dipole (as in Two-Poles) by which all other antennas are measured.
		Antennas with omni-directional radiation and gains of beyond 9dB are impractical owing to the fact that the focusing is directly related to the length (in wavelengths) of the antenna.
		Antennas do not somehow magically create power but simply focus the radiated RF into narrower patterns such that there appears to be more power coming from the antenna in the required direction.
	www.marcspages.co.uk /tech/antgain.htm (1108 words)

	Antenna Theory
		The geometry of the antenna and the proximity of near-by objects are the main controlling factors.
		The aperture of a dipole antenna is roughly the shape of a rugby ball (elliptical) when viewed from a point 90 degrees from the line of the conductor.
		Actual construction of these antennas is such that the antenna conductor is continued on down to the ground, where a matching network transforms the high impedance of the 1/8 wavelength long, single conductor, feed line to the low impedance of the line running to the transmitter.
	k9erg.tripod.com /theory.htm (1866 words)

	Gain of Helix
		The axial-mode helix antenna, first described by Kraus in 1947, is probably the most widely used circularly-polarized antenna, either in space or on the ground.
		An empirical expression for the maximum possible gain Gmax of the helical antenna as a function of its length L in wavelengths is:
		The gain is almost independent of wire diameter, or of the presence of a short feed stub between the ground plane and the start of the helix.
	www.tuc.nrao.edu /~demerson/helixgain/helix.htm (652 words)

	Measuring antenna gain
		One answer is to measure the antenna's gain against a known reference.
		As a precaution, the two antennas are swapped so that antenna #1 goes on the mast and uses the feedline formerly used by antenna #2.
		Given some care in measurements and a stable path, it is possible to determine the difference in the gain of the two antennas down to a fraction of a decibel.
	commfaculty.fullerton.edu /woverbeck/antgain.htm (779 words)

	How to Pick the Right Antenna
		All RF (in relation to antenna gain) starts out as the power that would be put out by a perfect point in space that would radiate the signal in all directions and create a perfect sphere of energy and is called an isotropic radiator.
		Panel antennas also have smaller side lobes and wider main lobes (a lobe would be a high power area, or the peaks on the charts above) making them better at eliminating multi-path and easier to aim.
		It was on his crank up TV antenna tower and we were not able to point the antenna in the exact area that we thought the tower was (too far away to see).
	www.odessaoffice.com /wireless/antenna/how_to_pick_the_right_antenna.htm (2144 words)

	antenna
		Therefore, antenna radiation patterns or plots are a very important tool to both the antenna designer and the end user.
		The collinear antenna was historically used by repeater sites, stacking various 1/2 wave dipole elements on top of each other for increased gain connected by some equipment to correct for phase error between the elements of the array.
		The antenna is about 3 dB more responsive in the direction of the slot than it is off the rear of the antenna.
	www.wlan.org.uk /antenna-page.html (4132 words)

	High gain antenna (Site not responding. Last check: 2007-11-07)
		The narrow beamwidth of a high gain antenna is an unfortunate tradeoff.
		But before the SOI begins, the high-gain antenna will be turned to point away from Earth, to serve as a protective shield against possible damage by dust...
		A medium gain antenna might be too weak, but a high gain antenna would be so directional you would need...
	www.designerdecals.com /high+gain+antenna.html (1022 words)

	Tips and tricks on how to build your own CB Antennas.
		This CB antenna consists of a driven element and four radial wires that act as a ground.
		If you are going to use this antenna with a store bought mount, the threads on the bolt on the bottom of the antenna should mate with the hole in the top of the mount's spring.
		Your base CB antenna system may be put up 20 feet higher than the highest point of the building or tree on which it is mounted; however, the highest point of the antenna must not be more than 60 feet above the ground.
	home.att.net /~wizardoz/cbmw/antenna_fabri.html (2767 words)

	Corner reflector antenna (Site not responding. Last check: 2007-11-07)
		In practice this angle is usually at 90 degree or 60 degree while 90 degree is easier to be matched although gain is lower.
		This might be the final key to tune-up such an antenna after radiator length is settled for a specific operating frequency.
		Following is a table that shows the general dimension of such antenna at UHF and VHF band (Fig.B).
	www.qsl.net /ve3rgw/corner.html (342 words)

	Antenna gain (Site not responding. Last check: 2007-11-07)
		Antenna gain is the sensitivity of an antenna in a particular direction compared with sensitivity of an isotropic antenna in any direction or a dipole antenna in the equatorial direction.
		For dish-type antennas gain is proportional to aperture (reflective area) and surface accuracy of antenna as well as the frequency being In general a larger aperture antenna has higher gain.
		An extended database of microwave common carrier antenna gain patterns (SuDoc C 60.10:90-267)
	www.freeglossary.com /Antenna_gain (384 words)

	CSVHFS Antenna Gain Measurements index (Site not responding. Last check: 2007-11-07)
		The Central States VHF Society has conducted Antenna Gain Measurements since its inception in 1967.
		Comparisons can be made between antennas measured in different years on the 50 MHz through 432 MHz bands because the same reference antennas have been in use for over 10 years!
		The Antenna Gain Measurements are currently (and have been for many years) conducted under the diligent guidance of Marc Thorson, WB0TEM and Kent Britain, WA5VJB.
	www.csvhfs.org /CSVHFANT.HTML (184 words)

	Definition: antenna gain (Site not responding. Last check: 2007-11-07)
		antenna gain: The ratio of the power required at the input of a loss-free reference antenna to the power supplied to the input of the given antenna to produce, in a given direction, the same field strength at the same distance.
		The gain may be considered for a specified polarization.
		), when the reference antenna is a linear conductor, much shorter than one quarter of the wavelength, normal to the surface of a perfectly conducting plane which contains the given direction.
	www.atis.org /tg2k/_antenna_gain.html (207 words)

	High Gain Antenna -- Facts, Info, and Encyclopedia article (Site not responding. Last check: 2007-11-07)
		The High Gain Antenna (HGA) is an (An electrical device that sends or receives radio or television signals) antenna with a focused, narrow radiowave beam width.
		This narrow beam width allows for more precise targeting of where you want the radio signal to go - also known as a (An antenna that transmits or receives signals only in a narrow angle) directional antenna.
		Most commonly referred to during space missions, these antennas are also in use all over (The 3rd planet from the sun; the planet on which we live) Earth, most successfully in flat, open areas where no mountains lie to disrupt radiowaves.
	www.absoluteastronomy.com /encyclopedia/h/hi/high_gain_antenna.htm (129 words)

	Antenna Gain & EIRP (Text)
		The gain of a 100% efficient antenna over an isotropic radiating or receiving antenna is given by:
		for area receiving antenna or telescope (78.5 m
		The Effective Isotropic Radiated Power (EIRP) is the apparent power transmitted towards the receiver, if it is assumed that the signal is radiated equally in all directions, i.e.
	www.coseti.org /9006-003.htm (154 words)

	Antenna Visualization (Site not responding. Last check: 2007-11-07)
		Identification of nulls in the antenna pattern is accomplished in a variety of visualization techniques, with and without other characterstics of the antenna radiation field being displayed.
		Some of the characteristics of the antenna field we can visualize are the gain pattern, the polarization sense pattern, and polarization tilt.
		Multiple antennas and passive obstacles in the vicinty can also be modeled and visualized.
	n5xu.ae.utexas.edu /antennavis (458 words)

	Radio Antenna with Active Gain
		The RF signal is direct-coupled from Q1's source terminal to the base of Q2, which is configured as a voltage amplifier.
		Transistor Q3 is used to match and isolate the gain stage from receiver's RF-input circuitry.
		The antenna is short pull-up type (42" to 86" long).
	www.designnotes.com /CIRCUITS/antenna.htm (211 words)

	High Gain Antenna Encyclopedia Article, Definition, History, Biography (Site not responding. Last check: 2007-11-07)
		The High Gain Antenna (HGA) is an antenna with a focused, narrow radiowave beam width.
		This narrow beam width allows for more precise targeting of where you want the radio signal to go - also known as a directional antenna.
		Most commonly referred to during space missions, these antennas are also in use all over Earth, most successfully in flat, open areas where no mountains lie to disrupt radiowaves.
	www.alienartifacts.com /encyclopedia/High_Gain_Antenna (321 words)

	Antenna on the Cheap (er, Chip) (Site not responding. Last check: 2007-11-07)
		While a directional antenna showing between 12 and 15db gain is impressive, it's also pretty large, physically.
		We realized that, if we were careful, we could fit a full wavelength inside the Pringles can itself (at a reduced total gain), but make the entire antenna much more compact.
		Over a clear line of sight, with short antenna cable runs, a 12db to 12db can-to-can shot should be able to carry an 11Mbps link well over ten miles.
	www.oreillynet.com /cs/weblog/view/wlg/448 (1624 words)

	ARRLWeb: Antenna Gain Measurement
		Antenna Gain Measurement -- Part 1 (1,012,708bytes, PDF file)
		Antenna Gain Measurement -- Part 2 (1,371,250 bytes, PDF file)
		Antenna gains in ham radio magazine advertisements, sometimes have little bearing on reality!
	www.arrl.org /tis/info/antgain.html (460 words)

	Antenna Gain to ERP
		A radio's transmitting power can be concentrated along the horizon by use of a GAIN antenna.
		Although you may still be transmitting with four watts of power, your EFFECTIVE RADIATED POWER (ERP) will be greatly increased.
		This table shows the effects of antenna gain on a transmitter with 4 watts of transmit power.
	www.firestik.com /Tech_Docs/gain_erp.htm (70 words)

	QuickerTek - Whip Pro Antenna for 15 and 17 inch PowerBooks (Site not responding. Last check: 2007-11-07)
		QuickerTek’s Whip Pro antenna gives AirPort, Extreme and Express users that extra boost in signal strength, stability and range.
		A stronger signal-to-noise ratio grabs and holds wireless signals better.
		You can use the PC Card [PCMCIA] slot and the antenna at the same time for maximum mobile options.
	www.quickertek.com /WhipProant.html (95 words)

	loose wire: RFID
		Thirdly, while it's true that most RFID tags are passive (without a battery) some are active (with a battery inside) meaning that they can be read over much longer distances -- between 100 and 300 ft (up to 100 metres) at present, I believe.
		Some of these items may not be commercially available yet, but it's shortsighted to suggest that RFID technology is not improving so quickly that it will not reach the point where it becomes an important social issue, including MI5's ability to gain access to your tomatoes.
		Still, there's clearly a lot of debate about this, and I was speaking to some RFID folk in Australia who say the security concerns are too far down the track to worry about, since RFID is still too young a technology to be really deployable.
	loosewire.typepad.com /blog/rfid/index.html (1282 words)

	Ham Antenna Software
		Antenna Design and Software From G4FGQ -- Loaded -- many antenna design programs, coax rating, ferrites and toroids, Groundwave propagation, much much more.
		EMMCAP Software for modeling of arbitrarily shaped wire structures and the computation of their electromagnetic behavior, including radiation and scattering problems.
		-- Polar diagram of your rotatable beam antenna actually looks like where it is operating.
	www.ac6v.com /antsoftware.htm (294 words)

	CB,Amateur and other Communications Radio Antenna System Evaluator Site
		This JavaScript program evaluates the performance of your antenna system, computing the consequences of SWR and feedline loss.
		Enter 2.2 for dipoles; add 2.2 for antennas rated in dBd
		If you have any questions, comments or you want to see something else added please e-mail me at kd6dks@hotmail.com
	www.softcom.net /users/kd6dks/antenna.html (235 words)

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