A yagi antennaside lobes in a two-dimensional power diagram (schematic, polar diagram)A multiband rotary directional antenna for Amateur Radio use

Discover great deals on the many top brand items available only on eBay!

Antennas

Most simply, an antenna (U.S.) or aerial (UK) is an electronic component designed to transmit or receive radio waves. The words "antenna" and "aerial" are used throughout this article with precisely the same meaning. more...

HomeHome
Accessories & CablesAccessories & Cables
AntennasAntennas
Audio & Speaker CablesAudio & Speaker Cables
Blank Tapes & CDsBlank Tapes & CDs
Brackets, MountsBrackets, Mounts
Cases, StorageCases, Storage
Maintenance & CareMaintenance & Care
ManualsManuals
Other Audio AccessoriesOther Audio Accessories
Other TV AccessorieOther TV Accessorie
RF ModulatorsRF Modulators
Selectors, SwitchersSelectors, Switchers
Surge Protection, FiltrationSurge Protection, Filtration
TV AntennasTV Antennas
TV StandsTV Stands
Video CablesVideo Cables
Video Selectors, SwitchesVideo Selectors, Switches
Wall Mounts & BracketsWall Mounts & Brackets
AmplifiersAmplifiers
CD Players & RecordersCD Players & Recorders
Cassette DecksCassette Decks
CrossoversCrossovers
DVD Players & Recorders DVD Players & Recorders
Digital Music...Digital Music...
Digital Video Recorders, PVRDigital Video Recorders, PVR
EqualizersEqualizers
Headphones, HeadsetsHeadphones, Headsets
Home Audio MiscHome Audio Misc
Home Theater ProjectorsHome Theater Projectors
Home Theater in a Box Home Theater in a Box
KaraokeKaraoke
MiniDisc PlayersMiniDisc Players
OtherOther
PreamplifiersPreamplifiers
ProcessorsProcessors
RadiosRadios
ReceiversReceivers
Remote ControlsRemote Controls
Satellite Radio Satellite Radio
Satellite, Cable TVSatellite, Cable TV
Shelf, Compact SystemsShelf, Compact Systems
Speakers & SubwoofersSpeakers & Subwoofers
Televisions TVTelevisions TV
Tuners, AM/FMTuners, AM/FM
TurntablesTurntables
VCRsVCRs
Vintage ElectronicsVintage Electronics
Wholesale LotsWholesale Lots

More specifically, an antenna is an arrangement of conductors designed to radiate (transmit) an electromagnetic field in response to an applied alternating electromotive force (EMF) and the associated alternating electric current.

Alternatively, if an antenna is placed into an electromagnetic field, that field will induce an alternating current upon the antenna, and EMF between its terminals. See radio frequency induction.

Overview

There are two fundamental types of antennas, which, with reference to a specific three dimensional (usually horizontal or vertical) plane, are either omni-directional (radiate equally in the plane) or directional (radiates more in one direction than in the other). All antennas radiate some energy in all directions but careful construction results in large directivity in certain directions and negligible power radiated in other directions.

By adding additional conducting rods or coils (called elements) and varying their length, spacing, and orientation, an antenna with specific desired properties can be created, such as a Yagi-Uda Antenna (often abbreviated to "Yagi"). Typically, antennas are designed to operate in a relatively narrow frequency range. The design criteria for receiving and transmitting antennas differ slightly, but generally an antenna can receive and transmit equally well. This property is called reciprocity.

The vast majority of antennas are simple vertical rods a quarter of a wavelength long. Such antennas are simple in construction, usually inexpensive, and both radiate in and receive from all horizontal directions (omnidirectional). One limitation of this antenna is that it does not radiate or receive in the direction in which the rod points. This region is called the antenna blind cone or null.

Antennas have practical use for the transmission and reception of radio frequency signals (radio, TV, etc.), which can travel over great distances at the speed of light, and pass through nonconducting walls (although often there is a variable signal reduction depending on the type of wall, and natural rock can be very defective to radio signals).

Antenna parameters

There are several critical parameters that affect an antenna's performance and can be adjusted during the design process. These are resonant frequency, impedance, gain, aperture or radiation pattern, polarization, efficiency and bandwidth. Transmit antennas may also have a maximum power rating, and receive antennas differ in their noise rejection properties.

Resonant frequency

The resonant frequency is related to the electrical length of the antenna. This is usually the physical length of the wire multiplied by the ratio of the speed of wave propagation in the wire. Typically an antenna is tuned for a specific frequency, and is effective for a range of frequencies usually centered on that resonant frequency. However, the other properties of the antenna (especially radiation pattern and impedance) change with frequency, so the antenna's resonant frequency may merely be close to the center frequency of these other more important properties.

Read more at Wikipedia.org


[List your site here Free!]

Antenna Tv Digital Hd 300 Mile Range Indoor 1080P 4K 16ft Coax Cable AccessoriesAntenna Tv Digital Hd 300 Mile Range Indoor 1080P 4K 16ft Coax Cable Accessories $3.64 Glomex Ra111Ais Ais antenna w/10M cable with connectors and accessoriesGlomex Ra111Ais Ais antenna w/10M cable with connectors and accessories $60.00
Offwire Accessories Antenna/Drive Time Kit - Magnet Mount Antenna with Rf CableOffwire Accessories Antenna/Drive Time Kit - Magnet Mount Antenna with Rf Cable $9.99 Am/Fm Antenna Cable And AccessoriesAm/Fm Antenna Cable And Accessories $14.99
Coaxial Antenna For Coaxial Cable WiFi Satellite AccessoriesCoaxial Antenna For Coaxial Cable WiFi Satellite Accessories $4.59 Garmin Gpsmap 295 Colormap with accessories (Yoke, cable, pwr, antenna)Garmin Gpsmap 295 Colormap with accessories (Yoke, cable, pwr, antenna) $167.00
Coaxial A/B Switch 100db. 5 To 900 Mhz Antenna/Cable Video Accessories Cm-83599Coaxial A/B Switch 100db. 5 To 900 Mhz Antenna/Cable Video Accessories Cm-83599 $55.48 Accessories Unlimited, Auppp18, 18 Ft Dual Lead Rg59U Coax Cable With 3 Pl-259'sAccessories Unlimited, Auppp18, 18 Ft Dual Lead Rg59U Coax Cable With 3 Pl-259's $36.95
Anritsu S331L Site Master Cable & Antenna Analyzer SiteMaster w/AccessoriesAnritsu S331L Site Master Cable & Antenna Analyzer SiteMaster w/Accessories $3,999.95 Ham radio antenna cable and accessoriesHam radio antenna cable and accessories $900.00
Yamaha Rx-V1900 Receiver 7.1 Avr Excellent Condition All Accessories IncludedYamaha Rx-V1900 Receiver 7.1 Avr Excellent Condition All Accessories Included $299.00 Tc35 Tc35I Mc35I Mc39I Module Accessories Sim Card Holder Antenna CableTc35 Tc35I Mc35I Mc39I Module Accessories Sim Card Holder Antenna Cable $4.89
Adapter cable, Abs car player, radio antenna adapter, male cable accessories,Adapter cable, Abs car player, radio antenna adapter, male cable accessories, $6.44 + Lot Oem Motorola Accessories Base Chargers Cables Adapters Antennas Clips Huge+ Lot Oem Motorola Accessories Base Chargers Cables Adapters Antennas Clips Huge $100.00
Accessories Unlimited, Aupp12, 12 Ft Rg58Au Coax Cable With Pl259's On Each EndAccessories Unlimited, Aupp12, 12 Ft Rg58Au Coax Cable With Pl259's On Each End $28.95 Car Aftermarket Audio Radio Antenna Adapter Plug Cable Accessories AdaptorCar Aftermarket Audio Radio Antenna Adapter Plug Cable Accessories Adaptor $3.52
Cb Radio Antennas and cable accessoriesCb Radio Antennas and cable accessories $35.00 Magnet Television Tv Accessories Cable Aerial Signal Antenna Indoor Digital HdtvMagnet Television Tv Accessories Cable Aerial Signal Antenna Indoor Digital Hdtv $6.04
Big Lot New Calrad Tv/Video Accessories Antenna Vcr Cable Switch Splitter 75 OhmBig Lot New Calrad Tv/Video Accessories Antenna Vcr Cable Switch Splitter 75 Ohm $10.00 Accessories Car Roof Radio Am/Fm Shark Fin Style Antenna Aerial Signal BlackAccessories Car Roof Radio Am/Fm Shark Fin Style Antenna Aerial Signal Black $9.99
Sennheiser Bnc to Bnc Coaxial Cable 1 Foot Antenna AccessoriesSennheiser Bnc to Bnc Coaxial Cable 1 Foot Antenna Accessories $9.99 Aerial Cable Antenna 1080P Hdtv Magnet Tv Accessories Signal Indoor DigitalAerial Cable Antenna 1080P Hdtv Magnet Tv Accessories Signal Indoor Digital $1.93
Tri Prc-152/148 Radio Dedicated Antenna Extension Cable Radio Accessories 24'Tri Prc-152/148 Radio Dedicated Antenna Extension Cable Radio Accessories 24' $27.88 Accessories Unlimited Auswr Cb Radio Antenna 10 watt Swr Test Meter w/ 3' CableAccessories Unlimited Auswr Cb Radio Antenna 10 watt Swr Test Meter w/ 3' Cable $28.95
Audiovox Accessories 4330422071 Coaxial Cable Antenna Wire , 100', BlackAudiovox Accessories 4330422071 Coaxial Cable Antenna Wire , 100', Black $20.67 Solight Antenna Connectors Antenna And Tv Accessories Antenna Cables And Conn.Solight Antenna Connectors Antenna And Tv Accessories Antenna Cables And Conn. $5.64
Car Stereo Antenna Cable for Toyota Camry Corolla Audio Accessories AdaptCar Stereo Antenna Cable for Toyota Camry Corolla Audio Accessories Adapt $11.99 Wireless Microphone Signal Gain Antenna Cable Diy Mic Accessories Black TncWireless Microphone Signal Gain Antenna Cable Diy Mic Accessories Black Tnc $7.91
Voxx Accessories Amp1450R Digital Signal Amplifier Accs For Indoor AntennasVoxx Accessories Amp1450R Digital Signal Amplifier Accs For Indoor Antennas $34.08 WiFi Antenna WiFi Rp-Sma Antenna Cable Accessories Attachment UniversalWiFi Antenna WiFi Rp-Sma Antenna Cable Accessories Attachment Universal $7.84
$19.59 Home Cable Antenna Rp-Sma To Ipx Folding Aerial Accessories Office 2.4Ghz RouterHome Cable Antenna Rp-Sma To Ipx Folding Aerial Accessories Office 2.4Ghz Router $2.02
Lot Of 8 Sennheiser Bnc to Bnc Coaxial Cable 1 Foot Antenna AccessoriesLot Of 8 Sennheiser Bnc to Bnc Coaxial Cable 1 Foot Antenna Accessories $44.44 Solight Antenna Cable 1,5m Antenna And Tv Accessories Antenna Cables And Conn.Solight Antenna Cable 1,5m Antenna And Tv Accessories Antenna Cables And Conn. $6.02
Antenna Cable -Mopar 56043089Af- AccessoriesAntenna Cable -Mopar 56043089Af- Accessories $44.02 Accessories Unlimited Aupl259C Male Uhf Crimp Connector For Rg58 Coax CableAccessories Unlimited Aupl259C Male Uhf Crimp Connector For Rg58 Coax Cable $14.99
Kaelus iVa 0627A Cable & Antenna Analyzer 560Mhz-2750Mhz - Standard AccessoriesKaelus iVa 0627A Cable & Antenna Analyzer 560Mhz-2750Mhz - Standard Accessories $3,995.99 Pz.Kpfw Iv Accessories (KwK37 & KwK 40 Barrles, Ammo, Mg34,Tow Cable, Aerial)Pz.Kpfw Iv Accessories (KwK37 & KwK 40 Barrles, Ammo, Mg34,Tow Cable, Aerial) $1.92
Rca Antenna Rabbit Ears Model Ant122R Audiovox Accessories Telescoping Cut CableRca Antenna Rabbit Ears Model Ant122R Audiovox Accessories Telescoping Cut Cable $19.99 Accessories Unlimited, Aupll18,18 Ft Dual Lead Coax Cable With A Pl259 & 2 LugsAccessories Unlimited, Aupll18,18 Ft Dual Lead Coax Cable With A Pl259 & 2 Lugs $29.95
Aerial Tv Accessories Antenna Indoor Signal Cable Hdtv Television 1080P MagnetAerial Tv Accessories Antenna Indoor Signal Cable Hdtv Television 1080P Magnet $1.85 Loran-c Antenna/ Transmit Antenna and cable accessoriesLoran-c Antenna/ Transmit Antenna and cable accessories $132.84
Television Signal Hdtv Tv Accessories Cable Antenna Indoor Aerial 1080P MagnetTelevision Signal Hdtv Tv Accessories Cable Antenna Indoor Aerial 1080P Magnet $5.87 Vintage Tv Antenna Wire B4612 50 Feet and Tv Accessories 3 Way Clips Lead 1970'sVintage Tv Antenna Wire B4612 50 Feet and Tv Accessories 3 Way Clips Lead 1970's $19.95
Adapter Cable, Abs Car Player, Radio Antenna Adapter, Male Cable Accessories, FaAdapter Cable, Abs Car Player, Radio Antenna Adapter, Male Cable Accessories, Fa $6.45
Click to see more Antennas items at www.ebay.com
Prices current as of last update, 09/15/20 12:20pm.

Home Contact Resources Exchange Links ebay