Can an enclosure surrounding a Tx antenna act as a receiving antenna?

In summary, the key point is that in order for an enclosure to act as an antenna, it must have a break in it, such as a slot, to allow for an EMF to be detected. Without this break, the enclosure will simply reflect the radiated fields. Additionally, if the enclosure is ideal with no imperfections, it will present as a pure reactance with no resistance to the transmitter. However, in real life, imperfections must be accounted for in order to calculate a realistic answer.
  • #1
genekuli
68
4
TL;DR Summary
If I put a metal enclosure, eg. cuboid, around a Tx antenna, can the metal enclosure, since it is completely surrounding the antenna, act as a receiver (a receiving antenna) even if it is not of any specific dimension relating to the frequency of the TX antenna radiation within it?
of course it would all have to be wired up correctly
 
  • Skeptical
Likes davenn
Physics news on Phys.org
  • #2
genekuli said:
of course it would all have to be wired up correctly
That's the key point, I believe. How are you going to wire up a metal cuboid to act as an antenna? An antenna develops a receive voltage at its output terminals as a result of the EM radiation generating differential currents and hence differential voltages. A cuboid doesn't have 2 halves like a dipole, and if you try to use it as a monopole with respect to a ground plane, I don't think the Tx antenna inside it will generate any differential currents or voltages with respect to the ground plane.

Do you have a particular application in mind? If you describe the application, we may be able to suggest some antenna geometries that could work. Or is this just a question that came up as you were learning about EM and antennas?
 
  • Like
Likes davenn and genekuli
  • #3
For the 'enclosure' to do other than just reflect the radiated fields, it needs to have a break in it (a slot, for instance) so that an EMF can be detected across it.
So if your enclosure is 'ideal' (silver plated and welded all around) then the transmitting antenna will present to the transmitter as a pure reactance with no resistance. It would give most transmitters a headache as it could deliver no power.

This is one of those irrisistable force meets an immovable object type questions. In real life, the setup can't exist so you'd have to allow some imperfection, like leakage through the enclosure. Once you do that, you can calculate some sort of a real answer.
 
  • Like
Likes genekuli

1. How does an enclosure surrounding a Tx antenna act as a receiving antenna?

An enclosure surrounding a Tx antenna can act as a receiving antenna through the phenomenon of electromagnetic induction. When a Tx antenna emits a radio frequency signal, it creates an electromagnetic field around it. This field can induce a current in the enclosure, essentially turning it into a receiving antenna.

2. What factors affect the effectiveness of an enclosure as a receiving antenna?

The effectiveness of an enclosure as a receiving antenna depends on several factors, such as the material and size of the enclosure, the frequency of the transmitted signal, and the distance between the Tx antenna and the enclosure. A larger and conductive enclosure made of materials with high permeability, such as iron or copper, will have a higher receiving capability.

3. Can an enclosure surrounding a Tx antenna act as a receiving antenna for all types of signals?

No, an enclosure surrounding a Tx antenna can only act as a receiving antenna for signals within a certain frequency range. This range is determined by the size and shape of the enclosure, as well as the material it is made of. For example, a larger enclosure made of conductive material will be more effective at receiving lower frequency signals, while a smaller enclosure made of less conductive material may only be effective for higher frequency signals.

4. Are there any potential drawbacks to using an enclosure as a receiving antenna?

One potential drawback of using an enclosure as a receiving antenna is that it may not be as efficient as a dedicated receiving antenna. This is because the enclosure is not specifically designed for receiving signals and may not have the optimal shape or size for the desired frequency range. Additionally, the enclosure may introduce interference or distortion to the received signal, affecting the overall quality.

5. How can I optimize the use of an enclosure as a receiving antenna?

To optimize the use of an enclosure as a receiving antenna, it is essential to consider the factors that affect its effectiveness. This includes choosing the right size and material for the enclosure, as well as positioning it at the appropriate distance from the Tx antenna. Additionally, using a dedicated receiving antenna may provide better results in terms of signal quality and efficiency.

Similar threads

Replies
10
Views
512
  • Electrical Engineering
Replies
9
Views
669
  • Electrical Engineering
2
Replies
36
Views
784
  • Electrical Engineering
Replies
24
Views
1K
  • DIY Projects
Replies
26
Views
2K
  • Classical Physics
Replies
12
Views
3K
Replies
14
Views
1K
  • Classical Physics
Replies
3
Views
602
  • Engineering and Comp Sci Homework Help
Replies
7
Views
869
  • Electrical Engineering
Replies
12
Views
1K
Back
Top