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English: Diagram of a J-pole antenna, a vertical end-fed half-wave omnidirectional transmitting antenna used in the shortwave frequency bands. It consists of a vertical element a half wavelength (/) long, fed in series with a quarter wavelength (/) transmission line stub, with the coaxial cable feedline (F) from the transmitter attached along the stub.
The J-pole antenna is an end-fed omnidirectional half-wave antenna that is matched to the feedline by a shorted quarter-wave parallel transmission line stub. [5] [1] [6] For a transmitting antenna to operate efficiently, absorbing all the power provided by its feedline, the antenna must be impedance matched to the line; it must have a resistance equal to the feedline's characteristic impedance.
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English: The image gives six circuit diagrams (schematics) for balanced line antenna tuners of the tuned-transformer type, discussed in the Wikipedia article "Antenna Tuner" or "ATU". It is an edited version of the original by JNRSTANLEY uploaded 2014-10-15.
A diagram contrasting a single antenna configuration with DAS A typical DAS node for the Videotron 3G network in Montreal, Quebec DAS deployed by Transit Wireless in New York City Subway to provide WiFi, cellular voice and data coverage. The RF node with three antennas was at the platform and another antenna near the stairs on the far side.
The ground rods create a ground plane under the antenna which increases the gain. The ground rods may extend horizontally from the base, but in antennas fed by coaxial cable as shown here they are usually sloped downward to increase the radiation resistance of the antenna from the 36 ohms of a quarter wave monopole closer to 50 ohms, so the ...
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English: Diagram of an umbrella antenna, a toploaded wire transmitting antenna used in the medium frequency (MF), low frequency (LF) and very low frequency (VLF) bands. It consists of a steel mast (grey) insulated from the ground, with diagonal wires radiating from the top, anchored to the ground in a circle around it. The feedline from the ...