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Topic: Collinear antenna array


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In the News (Wed 16 Dec 09)

  
  U.S. Patent: 5285211 - Coaxial collinear element array antenna - February 8, 1994
A linear array of coaxial elements of the prior art comprises a plurality of coaxial cables, each having a solid dielectric between the inner and outer conductors, wherein the inner conductor of one cable is connected to the outer conductor of the succeeding cable.
Performance of the prior art coaxial collinear array is degraded by the dielectric loading in three ways: first, the current distribution over the element sections is not uniform; second, the dielectric is lossy and contributes to antenna inefficiency; and third, the length per section is foreshortened, thereby adversely effecting the antenna gain.
1 is a representation of a coaxial collinear array antenna constructed in accordance with the principles of the invention.
www.everypatent.com /comp/pat5285211.html   (1754 words)

  
  CSS Antenna... Technical Notes   (Site not responding. Last check: 2007-10-28)
Antenna polarization: "In a specified direction from an antenna and at a point in its far field, is the polarization of the (locally) plane wave which is used to represent the radiated wave at that point".
Antenna pattern: The antenna pattern is a graphical representation in three dimensions of the radiation of the antenna as a function of angular direction.
Antenna directivity: The directivity of an antenna is given by the ratio of the maximum radiation intensity (power per unit solid angle) to the average radiation intensity (averaged over a sphere).
www.cssantenna.com /technotes/notes.html   (1677 words)

  
 Collinear antenna array - Wikipedia, the free encyclopedia
In telecommunication, a collinear antenna array is an array of dipole antennas mounted in such a manner that every element of each antenna is in an extension, with respect to its long axis, of its counterparts in the other antennas in the array.
Note: A collinear array is usually mounted vertically, in order to increase overall gain and directivity in the horizontal direction.
When stacking dipole antennas in such a fashion, doubling their number will, with proper phasing, produce a 3 dB increase in directive gain.
en.wikipedia.org /wiki/Collinear_antenna_array   (120 words)

  
 Highway vehicle identification system with high gain antenna - Patent 5164732
The roadway antenna comprises an antenna array traversing the highway lanes, and includes a collinear antenna array positioned in a reflector shield filled with a dielectric and buried in a flush-mount relationship with the roadway surface.
As shown, a single collinear array operating at 915 MHz is used for both transmitting and receiving with the use of a microwave directional coupler or circulator 126 wherein the triggering and interrogation signal is supplied by a conductor 127 and transponder response signals are received via the coupler and connector 128.
An antenna array 124 comprised of coaxial cable is mounted in the channel 123 inside a protective tubular housing 128 mounted somewhat centrally and internal of the reflective shield 123.
www.freepatentsonline.com /5164732.html   (8604 words)

  
 Collinear antenna array applicator - Patent 4700716
The antenna array applicator of claim 1 wherein, said impedance matching means is coupled to said antenna elements for enabling maximum power transfer to the antenna elements and minimizing stray leakage currents along the outside of the applicator.
The three collinear antennas are located in the distal section and a coaxial impedance matching transformer is provided in the proximal section in the form of a circumferential volume of dielectric material with a conductor external to the outer coaxial line.
At the proximal end of the antenna array 10, a coaxial impedance matching transformer is provided in the form of a dielectric cylinder 26 concentric with and external to the outer conductor 16.
www.patentmonkey.com /PM/PatentID/4700716.aspx   (5706 words)

  
 Collinear antenna array applicator - Patent 4700716
The antenna array applicator of claim 1 wherein, said impedance matching means is coupled to said antenna elements for enabling maximum power transfer to the antenna elements and minimizing stray leakage currents along the outside of the applicator.
The three collinear antennas are located in the distal section and a coaxial impedance matching transformer is provided in the proximal section in the form of a circumferential volume of dielectric material with a conductor external to the outer coaxial line.
At the proximal end of the antenna array 10, a coaxial impedance matching transformer is provided in the form of a dielectric cylinder 26 concentric with and external to the outer conductor 16.
www.freepatentsonline.com /4700716.html   (5460 words)

  
 Definition: collinear antenna array   (Site not responding. Last check: 2007-10-28)
collinear antenna array: An array of dipole antennas mounted in such a manner that every element of each antenna is in an extension, with respect to its long axis, of its counterparts in the other antennas in the array.
Note: A collinear array is usually mounted vertically, in order to increase overall gain and directivity in the horizontal direction.
When stacking dipole antennas in such a fashion, doubling their number will, with proper phasing, produce a 3-dB increase in directive gain.
www.its.bldrdoc.gov /fs-1037/dir-008/_1067.htm   (96 words)

  
 Antenna Products Corp. Optimizes Collinear Dipole Array Antenna by Electromagnetic Simulation
Antenna Products Corp. substantially improved the performance of a high-frequency collinear dipole array antenna by using MicroStripes electromagnetic (EM) simulation to evaluate a wide range of potential designs.
The simulation injected a broadband pulse into the antenna feed and the time domain response was captured by stepping through the transient phase long enough for it to attenuate to a steady state.
Ippolito took the simulation results for a two-module array and imported it into a general array factor program that he wrote to evaluate the effects of varying design parameters such as element spacing and orientation.
www.flomerics.com /news/news_details.jsp?newsId=417   (619 words)

  
 Business Software Review : Article 'Antenna'   (Site not responding. Last check: 2007-10-28)
The antenna noise is a function of the amount of noise that the feedhorn sees as it looks over the antenna rim towards the hot earth (which has a noise temperature of 290 K).
Antenna noise generally ranges between 30 and 50 K. The noise contribution of the LNB's internal circuitry is the other major source of concern.
The perfectly omnidirectional antenna is the isotropic antenna, a theoretical construct derived from actual antenna radiation patterns and used as a reference for specifying antenna gain and radio system effective radiated power.
www.business-software-review.org /DisplayArticle59143.html   (1317 words)

  
 iqexpand.com   (Site not responding. Last check: 2007-10-28)
collinear antenna array corner reflector counterpoise departure angle despun antenna diplex operation dipole antenna directional antenna direct ray effective antenna gain contour (of a steerable satellite beam...
Collinear antenna array, Darlington transistor, BiCMOS, Active laser medium, Omnidirectional antenna, Helical antenna, Dipole antenna, Yagi antenna, Unity, Nonlinear distortion, Instrument amplifier...
collinear antenna array - An array of dipole antennas mounted in such a manner that every element of each antenna is in an...
collinear_antenna_array.iqexpand.com   (367 words)

  
 Biconical antenna   (Site not responding. Last check: 2007-10-28)
A biconical antenna consists of an arrangement of two cone Conductor (material)s, which is driven by potential, charge, or a alternating magnetic field (and the associated alternating current) at the vertex.
A simple conical monopole antenna is a wire approximation of the solid biconical antenna and has increased bandwidth (over a simple monopole).
A bowtie antenna is simple broadband wire approximation of a biconical antenna (commonly used for Ultra high frequency transception).
read-and-go.hopto.org /Radio-frequency-antenna-types/Biconical-antenna.html   (124 words)

  
 W5GI Website - Mystery Antenna
The “mystery” part of the antenna comes from the fact that it is difficult, if not impossible, to model and explain why the antenna works as well as it does.
In short, the Mystery antenna is a sky wire that incorporates the advantages of a 3 element collinear and the G5RV antenna.
The second antenna was built with constructed with the coax cut to the same length as the wire.
www.w5gi.com /mysteryantenna.htm   (2031 words)

  
 Gain - Wikipedia, the free encyclopedia
In antenna design, gain is the logarithm of the ratio of the intensity of an antenna's radiation pattern in the direction of strongest radiation to that of a reference antenna.
If the reference antenna is an isotropic antenna, the gain is expressed in units of dBi (decibels over isotropic).
Often, the dipole antenna is used as the reference, in which case the gain of the antenna in question is measured in dBD (decibels over dipole).
en.wikipedia.org /wiki/Gain   (610 words)

  
 Ross's Antennas   (Site not responding. Last check: 2007-10-28)
The Quadix is a circularly polarized parasitic array, sort of a cross between a helix and a quad (or loop yagi).
The Simple Collinear is a high performance vertical omni for two meters that is simple to model, and simple and inexpensive to build, making it an improvement over the standard coax collinear antenna.
The HO Collinear is a 4 element horizontally polarized omni for two meters.
home.comcast.net /~ross_anderson   (182 words)

  
 antenna basics
Technically, antenna impedance is the ratio at any given point in the antenna of voltage to current at that point.
This is a a vertically polarised UHF Yagi antenna and it is orientated WSW or 225 degrees.
Rather than being omnidirectional (as a whip antenna would be) the loop antenna responds to the cosine of the angle between its face and the direction of arrival of the electromagnetic wave.
www.electronics-tutorials.com /antennas/antenna-basics.htm   (2838 words)

  
 [No title]
In this sense, the polarization of the antenna is the polarization of the plane wave it radiates.
Since the transmit antenna is considered to be a lossless isotrope (and the transmission line is considered to be lossless as well), all of the transmitter power is radiated equally in all directions.
Some of the factors that cause this variety are the height of the antenna, the orientation of the antenna, the length of the antenna, and the characteristics of the ground reflecting the wave.
www.ncjrs.org /txtfiles1/nij/185030.txt   (18671 words)

  
 Method and apparatus for hyperthermia treatment - Patent 4776086
These antenna are referred to by workers in the hyperthermia field as a dipole, or a sleeve dipole.
10, in this embodiment, the outer conductor 16 of the antenna array is terminated by a radially inwardly extending ring shown as section 16a and 16b.
A beam steering resistor 22 may be disposed along the longitudinal axis of the antenna in the path of inner conductor 20, as shown Alternatively, an eguivalent beam steering resistor 21 may be formed as a circular ring embedded in outer insulator 14.
www.freepatentsonline.com /4776086.html   (5529 words)

  
 Build the Coax Collinear Antenna   (Site not responding. Last check: 2007-10-28)
After completing the basic assembly of the collinear antenna, apply a small amount of RF with the antenna on the floor or ground.
Because a collinear antenna is hot with RF along the shield of the coax, it is necessary to prevent the RF from coming back through the coax.
If the eight ½ wave coaxial elements result in an antenna too long for your liking (over seven feet), then it is okay to use four ½ wave coaxial elements but the SWR may be slightly higher (Attach four ¼ wave vertical ground radials at the antenna feed point to help lower SWR.).
www.sadona.com /news/ant_coaxcol.html   (789 words)

  
 David Kittle's Collinear Antenna   (Site not responding. Last check: 2007-10-28)
Also, the antenna can be made on a circuit board, were the traces are etched from a printout from a CAD program.
With this knowledge, maybe a collinear antenna could be simulated and made with good results.
The bandwidth of the antenna also decreases with more segments because the wavelength will change with frequency and hence the dipoles will be out of phase.
homepages.wwc.edu /student/kittda/Prop   (487 words)

  
 802.11 2.4Ghz Low-Power 5dBi Vertical Collinear Antenna   (Site not responding. Last check: 2007-10-28)
Starting from bottom to top of the antenna, they are the RF connector/decoupler section with feedline and the elemental array section comprised of a meander-line coil, and the element tubing.
The 3/32 tubing is used for the antenna elements.
The important relationship is from the middle of the coil to the beginning of the brass tube element is 1/4 wavelength.
www.guerrilla.net /reference/antennas/2ghz_collinear_omni_lowpwr   (963 words)

  
 collinear antenna   (Site not responding. Last check: 2007-10-28)
quality antenna designed to take hurricane force winds, it is very feasible to built a collinear antenna for average use...
The collinear antenna was historically used by repeater sites, stacking various 1/2 wave dipole elements on top of each...
In telecommunication, a collinear antenna array is an array of dipole antennas mounted in such a manner...
yellowpages-gd.com /articles/46/collinear-antenna.html   (530 words)

  
 Method and apparatus for hyperthermia treatment (US4776086)
These antenna are referred to by workers in the hyperthermia field as a dipole, or a sleeve dipole.
The gap voltage excites antenna currents that flow on the outer conductor of the transmission line through the center conductor, continues down the line to the next feed gap.
Some of the electromagentic energy radiated by the antenna is strongly absorbed by the ferrite sleeve which becomes hot and provides a source of localized heat for heating a tumor site.
www.delphion.com /details?pn10=US04776086   (1959 words)

  
 Directional arrays
The pattern radiated by the collinear array is similar to that produced by a single dipole.
Since this type of array is in a single line, rather than in a vertically stacked arrangement, the use of too many elements results in an antenna several wavelengths long.
Effective arrays of this type have been constructed in which the elements are 0.7 and even 0.8 wavelength long.
www.tpub.com /neets/book10/42i.htm   (573 words)

  
 JF Collinear Array   (Site not responding. Last check: 2007-10-28)
The JF Collinear Array was described in an article written by Richard R. Schellenbach, in the November 1982 issue of QST.
Following are highlights from this article and the design concept from which we have built this great antenna array, complete with feed line, that covers all of the HF Amateur Bands from 80 meters through 10 meters.
It is worth noting that the JF Array radiates the main power lobe broadside to the wire and not off the ends as a conventional, harmonically operated antenna does.
airwaterkinginc.purification.com /jfarray.html   (837 words)

  
 2 meters antennas - XE1BEF WEB PAGE
The Tiny 2+1 As with any standard three element design, this three element direct connect antenna utilizes a reflector and a director to achieve gain.
A Simple Seven Element Yagi Antenna A JavaScript that quickly calculates the dimensions for a seven element Yagi Antenna.
Construct a Simple 5/8-Wavelength Vertical Antenna for 2 Meters (444,192 bytes, PDF file) QST September 1980, pp.
members.fortunecity.com /xe1bef/2meters-antenna.htm   (734 words)

  
 Collinear Antenna : Antennas: Collinear
Omni-Gain Vertical Collinear Antenna by WA6SVT - This rugged antenna, an omnidirectional collinear, is capable of surviving harsh environments.
The Simple Collinear - Wherever there is a need for a vertically polarized omni-directional antenna with gain, a collinear is used.
The vertically polarized collinear takes the form of two or more half waves in-line and in-phase, resulting in an omni-directional pattern with maximum radiation near the horizon.
www.dxzone.com /catalog/Antennas/Collinear   (434 words)

  
 802.11 2.4Ghz Vertical Collinear Antenna   (Site not responding. Last check: 2007-10-28)
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.
Starting from bottom to top of the antenna, they are the RF connector/decoupler section, the elemental array section, and the quarter-wave whip section at the top of the unit.
To facilitate the rapid construction of multiple antenna's, one should build a jig to assist in the construction.
www.guerrilla.net /reference/antennas/2ghz_collinear_omni   (2090 words)

  
 antenna
Therefore, antenna radiation patterns or plots are a very important tool to both the antenna designer and the end user.
Unfortunately, technical references containing slot antenna information rarely contain practical design information required to build such antennas reliably, and few experimenters have access to the resources needed to fully analyze the radiation properties of their antennas over wide bandwidths.
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)

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