I don't see why both definitions can't be 'true'. One doesn't exclude the other.
- Paul
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On Wednesday, August 22, 2012 7:47:07 PM UTC-5, amdx wrote:
resonant antenna [′res·ən·ənt an ′ten·ə]

(electromagnetism)

An antenna for which there is a sharp peak in the power radiated or

intercepted by the antenna at a certain frequency, at which electric

currents in the antenna form a standing-wave pattern.



McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright ©

2003 by The McGraw-Hill Companies, Inc.





I thought a resonant antenna was resistive without any reactance.

Mikek

On Tuesday, August 28, 2012 5:22:46 AM UTC-5, (unknown) wrote:
I don't see why both definitions can't be 'true'. One doesn't exclude the other.

The definition of a "resonant antenna" *should* exclude non-resonant antennas just as the definition of a "red car" should exclude non-red cars. A non-resonant antenna that is conjugately matched meets the definition of a resonant antenna. That seems to be ambiguous at best and at worst, a contradiction. Updating the definition:

resonant antenna (also applies to a conjugately matched non-resonant antenna) -
An antenna for which there is a peak in the power radiated or intercepted by the antenna at a certain frequency, at which electric currents in the antenna form a maximum current standing-wave pattern

So much for the myth that resonant antennas radiate better than non-resonant antennas. Consider the following two examples without transmission lines.

50 ohm Source---50 ohm load

100+j100 ohm Source---100-j100 ohm load

Which system has the most efficient power transfer efficiency?

Has anyone ever considered that if the coax is disconnected from a center-fed half-wavelength antenna, the antenna is no longer resonant and could instead be used for a non-resonant guy wire at that frequency?
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73, Cecil, w5dxp.com