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  Topic: Far Field radiation and Non Resonant Antennas
R. Fry

Replies: 11
Views: 12373

PostForum: Questions Related to Antenna Theory   Posted: Wed Jun 08, 2016 1:37 pm   Subject: An Elaboration on the Comments of G3TXQ:
For consideration/discussion, below are some clips on this topic from https://en.wikipedia.org/wiki/Electromagnetic_radiation . The bold font attribute was added to call attention to important points ...
  Topic: Far Field radiation and Non Resonant Antennas
R. Fry

Replies: 11
Views: 12373

PostForum: Questions Related to Antenna Theory   Posted: Mon Jun 06, 2016 1:20 pm   Subject: Re: Reference Books
... My thesis is that reactance does not radiate.
Agreed.

... If your disagreement is with a reference, kindly dispute with the author, I am not qualified to defend their work.
I have been agree ...
  Topic: Far Field radiation and Non Resonant Antennas
R. Fry

Replies: 11
Views: 12373

PostForum: Questions Related to Antenna Theory   Posted: Sun Jun 05, 2016 10:52 pm   Subject: Re: Electromagnetic Compatibility: Principles and Applicatio
... The radiation resistance is defined as that part of the antenna that contributes to the power radiated by an antenna. ... For an electrically small dipole or monopole antenna, where l, which is ...
  Topic: Far Field radiation and Non Resonant Antennas
R. Fry

Replies: 11
Views: 12373

PostForum: Questions Related to Antenna Theory   Posted: Sun Jun 05, 2016 11:20 am   Subject: Far Field radiation and Non Resonant Antennas
Properly matching the feedpoint Z of a non-resonant antenna to the transmission line connected there means that the r-f current and voltage at the feedpoint are in phase.

Other things equal, both t ...
  Topic: Farfield calculation for a scattering object
R. Fry

Replies: 1
Views: 5676

PostForum: Questions Related to Antenna Theory   Posted: Wed Jun 10, 2015 10:42 am   Subject: Farfield calculation for a scattering object
Depending on how accurately you construct the physical model of this situation, NEC (Numerical Electromagnetics Code) can produce good insight toward answering your questions.

In general, VHF/UHF s ...
  Topic: Dipole antenna characterization
R. Fry

Replies: 3
Views: 7778

PostForum: Questions Related to Antenna Theory   Posted: Wed Mar 11, 2015 10:33 am   Subject: Dipole antenna characterization
The inner surface of the outer conductor of a coaxial cable carries the same r-f current magnitude as the outer surface of the inner conductor, just 180 degrees out of phase with it.

When a coaxial ...
  Topic: Why does an antenna work even though only 1 end connects?
R. Fry

Replies: 9
Views: 14676

PostForum: Questions Related to Antenna Theory   Posted: Sun Feb 08, 2015 1:53 pm   Subject: Why does an antenna work even though only 1 end connects?
Maybe another person will respond to your questions better than I did.

I do suggest that you study antenna engineering texts and other areas of antenna-theory.com, where many of your answers can be ...
  Topic: Why does an antenna work even though only 1 end connects?
R. Fry

Replies: 9
Views: 14676

PostForum: Questions Related to Antenna Theory   Posted: Sun Feb 08, 2015 12:29 pm   Subject: Why does an antenna work even though only 1 end connects?
"current"... This means "electrons flowing", doesn't it?
Yes

"r-f current" ... This is still electrons flowing somewhere, isn't it?
Yes

"2nd conductor" ...
  Topic: Why does an antenna work even though only 1 end connects?
R. Fry

Replies: 9
Views: 14676

PostForum: Questions Related to Antenna Theory   Posted: Sun Feb 08, 2015 10:09 am   Subject: Re: Open ended
...Take for example my 27mhz radio-controlled car transmitter, and the corresponding receiver: both of those antennas are literally bits of wire soldered onto the circuitboard at only 1 end. What ma ...
  Topic: Why does an antenna work even though only 1 end connects?
R. Fry

Replies: 9
Views: 14676

PostForum: Questions Related to Antenna Theory   Posted: Sat Feb 07, 2015 1:01 pm   Subject: Re: Electro MAGNETIC - is that the clue?
...Is this in fact what's going on?...
The schematic included in the OP does not show how those components are constructed.

The antenna shown there radiates because (typically in the VHF spectrum) ...
  Topic: Feeder SWR & power loss
R. Fry

Replies: 22
Views: 41404

PostForum: Questions Related to Antenna Theory   Posted: Sat Jul 26, 2014 11:22 am   Subject: Feeder SWR & power loss
... 50 ohm receiver powers a 50 ohm load...
For some additional input -- I have taken part in factory tests of
high-power Class C single-tube/tuned cavity FM broadcast transmitters
driving 50-ohm t ...
  Topic: Feeder SWR & power loss
R. Fry

Replies: 22
Views: 41404

PostForum: Questions Related to Antenna Theory   Posted: Mon Jul 14, 2014 11:15 am   Subject: Feeder SWR & power loss
...For the radio to deliver power to a 50 Ohm system, it has an intrinsic 50 Ohm impedance. As a result, reflected power is absorbed within the transmitter.
Just to note that if the source impedance ...
  Topic: How do I abide by FCC regulations?
R. Fry

Replies: 9
Views: 13721

PostForum: Questions Related to Antenna Theory   Posted: Sat Jan 25, 2014 7:57 pm   Subject: How do I abide by FCC regulations?
Likely so, if your application fits the FCC provisions permitted for such devices.
  Topic: How do I abide by FCC regulations?
R. Fry

Replies: 9
Views: 13721

PostForum: Questions Related to Antenna Theory   Posted: Sat Jan 25, 2014 7:01 pm   Subject: How do I abide by FCC regulations?
FCC 15.209 also applies to intentional radiators. Here is a clip from the first part of it:

15.209 Radiated emission limits; general requirements.

(a) Except as provided elsewhere in this s ...
  Topic: How do I abide by FCC regulations?
R. Fry

Replies: 9
Views: 13721

PostForum: Questions Related to Antenna Theory   Posted: Sat Jan 25, 2014 5:07 pm   Subject: How do I abide by FCC regulations?
I did make an error in a data entry for my earlier post (sorry). If the 0.5 V/m field limit you first posted is accurate, then your antenna input power would indeed be 45.7 mW, not 45.7 nW.

Howeve ...
 
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