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Questions tagged [far-field]

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finding polarization of radiated far-zone electric field

I am given a question in which I have to find the polarization of the radiated far-zone electric fields when phi is 0 and 90. Why are the following formulas used respectively? For phi = 0 $$ E_\...
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1answer
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Transformer basics: Why don't they shift phase by about 90°?

I learned that current is induced in a conductor by a changing magnetic field. According to this, it would follow that the secondary voltage (sinusoidal input) of a transformer should peak when the ...
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3answers
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The electric and magnetic components of far field EMR and shielding thereof

This is a newbie question. I'm pretty sure of the answer, but I would like confirmation. I found this thread in this forum that came close to what I was looking for, but I think my question is ...
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1answer
88 views

Phased array minimum size

I want to know two things,how big does the phased array needs to be to form proper beam and what is the smallest area the beam can be focused.I learned little bit about lasers and with focal lense,the ...
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3answers
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What are the extra lines on this farfield plot?

This is a plot from CST microwave studios of the farfield beam pattern of an antenna. I'm having trouble understanding why the plot isn't single-valued (2nd red circle) and also why there are blue ...
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1answer
301 views

Relationship between electric field at aperture and field at distance

I'm new to this forum and turned here because I have no other help to turn to. In studying antenna theory and I came across the relationship between E0(Electric field at aperture) and Er(Electric ...
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2answers
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How is the minimum reasonable distance for the far field of a dipole antenna calculated?

First let me try to explain what I think the near field is about: At very close ranges, due to the differences between instantanous voltage and current on each small segment of an antenna at any ...
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1answer
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near field power density formula for a dipole antenna

I am looking for a formula for near field power density from a dipole antenna antenna. Is cylindrical model is sufficient? Do I have to consider ground reflection too? Please share your ideas?
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2answers
781 views

Horn antenna Radiation pattern

Ok This might sound dumb but I am trying to get an equation for the radiation intensity of a pyramidal horn antenna in spherical coordinates. I got a whole bunch of books and they all have the same ...
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3answers
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What's radiating on my PCB?

I recently did a proper EMC test on a PCB of mine. It failed the test, and seems to be radiating in the 300MHz - 1GHz region, with peaks every 50MHz, and little peaks on the 25MHz. Looking at the ...