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What does antenna tuner do?
An antenna tuner (and any of the names in the list below) is a device that is inserted between a radio transmitter and its antenna; when properly adjusted (tuned) it improves power transfer by matching the impedance of the radio to the impedance of the antenna, as it appears end of the feedline connected to the antenna …
What is standing wave in transmission line?
A standing wave consists of waves moving in opposite directions. These waves add to make a distinct magnitude variation as a function of distance that does not vary in time. To see how this can happen, first consider that an incident wave V+0e−jβz, which is traveling in the +z axis along a lossless transmission line.
What is standing wave antenna?
In electronics, standing waves form when an electromagnetic wave traveling on an interconnect reflects off of an interface with an impedance mismatch. When the reflected wave and incident wave are perfectly in-phase, a standing wave can form that appears as a stationary sinusoid along the length of the interconnect.
What do you mean by standing waves?
Standing wave, also called stationary wave, combination of two waves moving in opposite directions, each having the same amplitude and frequency. The phenomenon is the result of interference; that is, when waves are superimposed, their energies are either added together or canceled out.
What does an antenna tuner do to a dipole?
300-ohm ladder line to a dipole requires a 4:1 balun to bring the impedance down to a range the transmitter can handle, which is typically 50-75 ohms, resistive, to keep the transmitters within their limits. So what does an antenna tuner do? Does it reduce the SWR (loss) on the feedlines?
How is the tune up of a chip antenna done?
Chip antennas pose a harder problem because they cannot be modified. RF designers using Chip antennas need to provide locations for matching components. The primary tool used for the tune-up is a Vector Network Analyzer (VNA).
Where is the coaxial connector for antenna tune up?
The coaxial RF connector is placed at the other end of the transmission line near the balun. Normally the connector would be used to make conducted measurements of RF signals. However, for the antenna tune-up we can physically rotate the connector by 180° and probe the antenna.
How does a VSWR work with an antenna tuner?
Whether part of you antenna tuner or a separate instrument a VSWR Meter consists of a directional coupler that samples forward and reflected voltage, a detector diode and apply the detected voltage to metering circuit. The metering circuit can have a switch to select forward and reflected power or dual meters.