All Questions
33
questions
1
vote
0
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42
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Dipole antennas and the $B$ field
A dipole antenna responds to the electric component of a EM wave. Does the magnetic component of a EM wave have any effect on the performance of a receiving dipole antenna?
- 55
1
vote
2
answers
97
views
Electromagnetic field of dipole antenna
Why do dipole antennas generate EM waves by alternating electric fields instead of alternating magnetic fields?
Why don't alternating magnetic poles detach the magnetic field like how it can do so ...
- 156
1
vote
2
answers
52
views
Minimum frequency for a dipole antenna to work
Does a dipole antenna need a minimum frequency of AC to make the electric field detach and propagate?
- 156
-1
votes
1
answer
93
views
How does an antenna work?
I'm looking for a model of an antenna that would explain how it works an in particular where the values of impedance like 36.5 ohms come from. I've tried looking but everything i found was overly ...
- 31
2
votes
4
answers
166
views
Dipole Antenna: Electromagnetic Wave
I have read about wave propagation and dipole antennas here. I do not understand how a single electromagnetic wave (i.e. the electric field in particular - I can come up with the magnetic field later) ...
0
votes
1
answer
149
views
Wave Propagation: Dipole Antenna
I was watching the following video here. This video explains the following image below represents an electric field generated from a dipole antenna. How does a single wave of electromagnetic radiation ...
2
votes
1
answer
251
views
Electric field of dipole antenna
I have seen that the electric field of a dipole antenna detaches and propagates.
For a section of the detached electric field, will the antenna experience recoil if the detached field moves a charged ...
- 156
3
votes
3
answers
302
views
Deforming LC circuit into dipole antenna
I once learned in school, and as far as I know this is also a common thing in many introductory physics books, that a parallel LC circuit can be "bent open" into a dipole antenna, like this:
...
0
votes
0
answers
24
views
How determine the angle theta if short dipole is polarized along different vectors?
i am trying to understand the solution: (i have attached q & solution key)
see part d,e,f how do we visualize rotation for gain function given different vector direction of polarization (i.e. in d,...
- 1
2
votes
1
answer
105
views
What is the $\frac{1}{r^2} $ term in the electric field of a Hertzian dipole equations?
Taking common equation for the electric field of a Hertzian dipole from Wikipedia:
$${\displaystyle {\begin{aligned}E_{\theta }=i{\frac {\zeta _{0}I\delta \ell }{4\pi }}\left({\frac {k}{r}}-{\frac {i}{...
- 155
0
votes
1
answer
82
views
What are the sources of electric and magnetic fields that produce lights?
Electromagnetic waves are formed as a consequence of the interference of electric and magnetic fields. I wonder where are these fields coming from that form the light? Does the fields have to be ...
1
vote
2
answers
122
views
Question about the electric dipole radiation [duplicate]
I can understand why an oscillating electric dipole emmits electromagnetic rdiation-charges are constantly accelerating. But how come fixed electric dipoles with varing charges also emmit E-M ...
- 75
1
vote
3
answers
566
views
How a dipole should behave in order to produce an electromagnetic field?
I am trying to understand what an electric dipole "has to do" to produce electromagnetic waves. I know that an oscillating electric dipole will produce EM waves and by oscillating electric ...
- 941
0
votes
1
answer
321
views
How do I calculate the induced voltage on a finite antenna?
I'm trying to calculate (numerically) the induced voltage on a half-wave dipole caused by a moving charge as a function of time.
Up to this point the way I have been doing this is using the formula
$$...
- 1
4
votes
2
answers
360
views
Has anyone ever put a magnetic or electrostatic dipole on a rotating shaft, spun it and demonstrated reception of a propagating wave in the far-field?
The question If I create a varying electric field and it will then create a varying magnetic field, so will it also create light? Will I see a light ray? got me thinking.
I'm pretty sure that if I ...
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