Re: How many joules --> e.m. waves?

[LUDWIK KOWALSKI <kowalskil@alpha.montclair.edu>]

On April 17 1997 Mark Shapiro (referring to emitting antennas) wrote:

> If the diameter of the loop is about lamda/5, then the circumference of 
> the loop is close to a half-wavelength (just what you need to maintain a 
> standing wave pattern on the antenna)! These are very efficient radiators.

This suggests that the efficiency of emission versus d (the diameter of 
the antenna) should have maxima at "standing wave patterns", that is when 
Pi*d is equal to lambda/k (k=2,3,4,...). This is not confirmed by the 
radiation resistance formula below (from Bob Sciamanda). Any comment?

   Rrad=19200*(d/lambda)^4    effic=Rrad/(Rohmic+Rrad)
                                                          Ludwik Kowalski
P.S.
There was an error in the calculation of the numerical coefficient for 
the Rrad formula in my last message but this has nothing to do with the
present question.