Re: Power Beamed Via Microwaves

BobG wrote:
>
> PB:
> Depends on the antenna. Different topologies can have markedly
> different
> impedances.
> ===============
> Well stupid me. All this time I thought the idea of an antenna was to
> match the impedance of free space? 377 ohms? 600Vx600V/377ohms=1KW
> Everyone agrees I assume?

I don't understand "impedance of free space" but suspect you
are working up to some falsehood. What is it?


--- Graham Cowan, former hydrogen fan
http://www.eagle.ca/~gcowan/Paper_for_11th_CHC.html
boron as energy carrier: real-car range, nuclear cachet
.

Relevant Pages

  • Re: Is antenna a transducer to 377 ohms?
    ... That is an antenna itself has no effect on the fundamental u and e of the media in which it is immersed. ... After all the antenna is very small, and free space is very large, and so a tiny antenna cannot change u and e everywhere! ... The *intrinsic* impedance of free space is 377 ohms. ... The *wave* impedance of an EM wave in that medium is 377 ohms if it's a plane wave in the far field of a radiator, and some other value if it's close to an antenna or other conductor or dielectric. ...
    (rec.radio.amateur.antenna)
  • Re: Is antenna a transducer to 377 ohms?
    ... The feedpoint impedance of an antenna is usually 50 or 75 ohms. ... a propagation media in field theory, that governs the ratio of the E to H ...
    (rec.radio.amateur.antenna)
  • Re: HIGH Q CAPS FOR VLF LOOP ANTENNA?
    ... The loop allows you ... In terms of performance relative to an isotropic antenna it ... It displays an impedance of: ... Just compare that to the 2 Ohms you hoped for and see what happened. ...
    (rec.radio.amateur.antenna)
  • Re: Coupling a T2FD to a S350DL
    ... This is an example of the 'traditional' 9:1 impedance transformer ... narrow bands of frequencies where the antenna impedance is naturally ... in following, and since UNUN was coined from balun, I would expect UNUN ...
    (rec.radio.amateur.antenna)
  • Re: balun spec depending on coax impedance
    ... At different frequencies the antenna will have different impedances ... Antenna reactance and impedance are two different things. ... The first case is hundreds of ohms and the second about 72 ... For a single wire Marconi antenna the wire diameter and the height of ...
    (rec.radio.shortwave)