[Elecraft] E-H Antenna Simulation in NEC

[Trevor Day]

Thank you for your considered (and swift) reply John.  I suppose I 
really ought to try and find the time to catch up with the theory.   I 
will let you know if and when I find out where my RF is going :-)

Trev G3ZYY (must get back to work; its fortunate I work from home)

In message <000e01c2e237$048ec7e0$6601a8c0@johnp4>, "John, KI6WX" 
<ki6wx@pacbell.net> writes
>Trev;
>The NEC software is based on a solution of Maxwell's Equations.  For wire
>types of structures, it solves Maxwell's Equations using the Electric Field
>Integral Equation.  For surface types of structures, it solves them using
>the Magnetic Field Integral Equation.  The program is capable of solving
>complicated structures.  Its accuracy and limitations are well documented in
>the scientific literature, and it can easily solve a fairly simple antenna
>structure such as described in the EH Antenna patent.
>
>So the real question is does the EH Antenna embody a new method of
>electromagnetic radiation that violates Maxwell's Equations?  I would place
>my money on Maxwell's Equations since they have survived for more than a
>century and are still considered a exact solution for electromagnetic
>radiation.
>
>The EH Antenna is a conventional antenna fed by a matching network.  The
>patent states "The phasing and matching network aligns the relative phase
>between the current and the voltage of the radio frequency power signal so
>that the H-field component of the corresponding electromagnetic signal is
>nominally in time phase with the E-field component".  This is exactly what
>happens in every antenna and is called the Poynting vector.  If the E and H
>fields are not in time alignment, the antenna will not radiate.
>
>I can't tell you what is happening to the power feeding your antenna.
>However, it is going to one or more of the following places:
>- Radiation from the antenna
>- Power dissipation in the antenna
>- Power dissipation in the matching network
>- Radiation from the coax
>- Power dissipation in the coax
>- Power dissipation in the transmitter (most people don't realize that
>transmitters can dissipate power that is not radiated by the antenna)
>
>You will need to do a carefully controlled set of experiments to determine
>where the power is going in your setup.
>
>-John
> KI6WX
>
>> Forgive me for asking this, its a serious question.  Does the EHs
>> 'claimed' method of operation not make the use of NEC as a model
>> useless? Surely NEC algorithms are based upon conventional antenna
>> theory?.
>>
>> Also, If the EH matching arrangement is that poor, where does the power
>> go?  My home-made EH does not even get warm and neither does the 4 foot
>> of coax feeding it.
>>
>> Trev G3ZYY
>>

-- 
Trevor Day