Plasma wire -- turning an antenna on and off very quickly

In summary, this article discusses an inventor who claims it is possible to turn an antenna on and off quickly using a fluorescent light bulb as a conductor. It has a few limitations, including that the tube can only operate at a few kHz, and the RF power itself would fire the tube at power levels above a few tens of watts. If used for receiving, the tube will introduce a very high noise level.
  • #1
arydberg
244
31
Someone asked if it was possible to conduct electricity through a wire with a plasma. I ran across a article about a inventor who wanted to turn a antenna on and off very quickly. He said it was possible to do this by using a florescent light bulb as a element in the antenna. When a high voltage was applied to the tube it became conductive but when the high voltage was turned off it became non conductive.
 
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  • #2
Sounds accurate, that's what happens with lightning in the atmosphere, when the trails are forming they cause plasma channels which conduct the main discharge.
arydberg said:
I ran across a article about a inventor who wanted to turn a antenna on and off very quickly.
If you want more information you would have to supply a link or a specific reference...
 
  • #3
The transmit/receive switches in early radar sets were based on small gas discharge tubes that conducted during transmit. The impedance mismatch created by the gas discharge in the line to the receiver reflected energy and so protected the sensitive receiver mixer diodes from the transmit energy. Those TR switches could switch on and off at 10kHz.
https://en.wikipedia.org/wiki/Duplexer#Transmit-receive_switch
 
  • #4
arydberg said:
Someone asked if it was possible to conduct electricity through a wire with a plasma. I ran across a article about a inventor who wanted to turn a antenna on and off very quickly. He said it was possible to do this by using a florescent light bulb as a element in the antenna. When a high voltage was applied to the tube it became conductive but when the high voltage was turned off it became non conductive.
This idea has a number of limitations.
1) The tube can only operate at a few kHz, whereas transmitters can often be pulsed much faster than this - so why do it?
2) The RF power itself would fire the tube at power levels above a few tens of watts.
3) If used for receiving, the tube will introduce a very high noise level. In fact these tubes are used as noise sources.
 

Related to Plasma wire -- turning an antenna on and off very quickly

1. What is plasma wire?

Plasma wire is a type of antenna made up of a thin, flexible wire coated with a conductive material and surrounded by a gas-filled tube. The gas inside the tube is ionized, creating a plasma state that allows for extremely fast switching on and off of the antenna.

2. How does plasma wire work?

The gas inside the plasma wire is ionized by an electrical current, creating a plasma state. This plasma state allows for the rapid movement of electrons, which enables the antenna to be turned on and off very quickly. This allows for faster and more efficient transmission of signals.

3. What are the advantages of using plasma wire for antennas?

Plasma wire antennas have several advantages. They can be turned on and off at a much faster rate than traditional wire antennas, making them ideal for applications that require quick signal switching. They also have a smaller physical footprint, making them more compact and lightweight. Additionally, they have a wider bandwidth and can operate at higher frequencies than traditional antennas.

4. What are some potential applications of plasma wire antennas?

Plasma wire antennas have a wide range of potential applications. They can be used in telecommunications, satellite communication, and radar systems. They are also being explored for use in military and defense applications, as well as medical imaging and research.

5. Are there any limitations or challenges to using plasma wire antennas?

One of the main limitations of plasma wire antennas is their sensitivity to environmental factors such as temperature and pressure. They also require a high voltage power source to maintain the plasma state, which can be a challenge to implement in some applications. Additionally, the gas inside the tube may need to be replenished periodically, adding to the maintenance and cost of using plasma wire antennas.

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