Re: NEC-LIST: Letter from Grimes

> Gentlemen
>
> Collin's paper attacks a Grimes and Grimes work, the JEWA paper, which we
> had pointed out in a subsequent 1999 Radio Science paper was incorrect.
> Since the Editor handling Collin's paper never contacted us about his work
> (nor allowed a rebuttal) what is left is Collin's trashing of a paper we had
> already said, in print in a widely read journal, was wrong.
>
> The JEWA paper uses frequency domain analysis which is fine for some
> specific antenna designs, albeit common ones, but is not a general technique
> suitable for all radiation sources. This is fact. For a general antenna
> design time domain analysis must be used. The reason is simple enough,
> information is lost in the frequency domain that is not in the time domain.
>

I personally question the validity of these statements regarding the time
domain and frequency domain. The solution to any EM problem can be found in
Maxwell's equation and should be valid regardless of whether a time domain or

frequency domain analysis is used. It is my opinion that a rigorous time
domain analysis or a rigorous frequency domain analysis of any antenna problem
should yield the same result. Certainly, there may be aspects of the problem
where a time domain or frequency domain analysis may be easier or may yield a
different perspective, insight or understanding of the problem. However, if a
time domain and frequency domain analysis lead to a different result or
conclusion, I would suspect a problem somewhere.

> No one, to our knowledge, has found any errors in the time domain results
> initially presented in the Radio Science paper attached, placed in
> perspective in the Q review paper attached (which summarizes the issue of Q,
> it's determination, and where Collin's errors are pointed out for the reader
> to which Collin has made no response), and tied together from an
> electromagnetics perspective (with an improved technique) in the recent book

> The Electromagnetic Origin of Quantum Theory and Light published by World
> Scientific. We also gave an hour lecture on this at the recent PIERS
> conference, the slides of which are downloadable from
>
> http://www.ee.psu.edu/grimes/publications/
>
> Our point is simple: Determination of radiation Q in mixed modal fields
> requires use of the time domain. The frequency domain is only correct with
> certain limited radiating structures due to missing phase information. When
> one does the general, complete math correctly a considerable amount of
> insight into physical phenomena regarding electromagnetic emission and
> quantum theory becomes clear. Whether that means we can build a zero-Q
> antenna is an open question, certainly mother nature can.... atoms support
> wavelength to size ratios of hundreds to thousands yet apparently don't have
> any problems with reactive energy storage.
>
> Why don't you guys read the papers and do the math. A proofs a proof, if

> the math is wrong we would be delighted to know about it. If the math is
> correct then I suggest the EM community might be well advised to consider
> the consequences of it.

Herein may lie a fundamental problem. "Correct Math" in and of itself, may
not necessarily be sufficient to support the conclusions. Fundamentally more
important than an analysis of the algebra is an in-depth understanding of any
assumptions or approximations used in the mathematical analysis. The
mathematical analysis may be exactly correct in terms of the algebra.
However, if it begins with a fundamental misconception or incorrect
assumption, the conclusion may be incorrect, even though the "math" appears to
support it.

>
> I would also suggest if you approach the results of our experimental work
> without bias you might find something interesting going on there. While
> such an antenna is not going to be sold commercially in the near future

> there are clues there for people interested in this field and have the time
> and resources to pursue it.
>
> Respectively, Craig Grimes
>

In fairness to your work and perspective, I intend to analyze the case of the
orthogonal crossed electric dipoles to see if I agree or disagree with your
results.

Sincerely,

Steven Best

-- 
The NEC-List mailing list <nec-list_at_gweep.ca>
http://www.gweep.ca/mailman/listinfo.cgi/nec-list