Thoughts about antenna engineering
27th.August 2005 / 16.8.06 / 4.11.08

My opinion regarding computer simulation programs

Computer Simulation Programs (CSPs) like NEC and
its family (EZNEC, NEC2, MMANA etc.)
may have a
very high value in optimizing antenna systems of well
known structures.
But in order to search and evaluate new types of antennas,
it seems to me questionable to use such programs.

The programs are based on formulas, which were developed
to describe the behaving of antennas of well known structures.

Note especially this >>> antenna simulation with NEC

All formulas have a validity range, and using them outside
this range may lead to completely wrong results.
Unfortunately, this is mostly disregarded in educating EEs,
which is in my opinion one of the main reasons, why large
engineering companies have lost their reputation,
their customers, and finally had to fire thousands
and tenthousands of employees ...
(e.g. BBC Brown Bovery Company and similar companies).

It is not done by teaching formulas and the mathematical
tools with the ability to write long mathematical derivations.
Most important is, to understand mentally all used formulas
and to be creative. That is the basis of successful engineering.

All used formulas describe an idealized behaving of
structures, disregarding small effects which remain unnoticed
under standard conditions.

Most people are very impressed by the beautiful diagrams
produced by these programs and think, that the computer
is modeling the full reality.

The result is good, if the evaluated structure corresponds to
the program, and if the environment is specified correctly.

The output provided by these programs may represent very closely
the reality, but it also may be completely wrong.

When searching new concepts and evaluating new ideas,
the only correct way is by doing experiments in real world.
Measuring the results may lead to new formulas which
describe this behaving, and using these new formulas in a CSP
helps then to further optimize the construction.

That's the way new constructions and concepts are found.

My personal experience in high tech engineering duringthe last
3 decades demonstrated very clearly, that large companies
lost millions and millions of dollars due to misuse of very
good formulas and programs - just by disregarding
the validity range of these very important engineering tools,
or caused by one dimensional thinking.

Just a simple example:
In the 1960s we developed the first phone line modems.
They operated at 200, 300, and 600 bps.
We were told by our professors, that the maximum speed
that ever could be reached would be 3800 bps, as the phone
line cuts frequencies above abt. 3800 Hz.
You know what bps rate today is possible over the phone line ...
They simply could not imagine, that you may combine
phase-, amplitude-, and frequency modulation simultaneously
in new techniques!

A further example:
Caused by misunderstanding of the applied formulas, a loss
of over 40 million dollars resulted in the development of a high
tech military product, the group was lead by doctors in Physics
and Mathematics ...

Even in large companies such tremendeous errors may not
occur frequently, as this will lead to that what happened ...

Similar things happen today in new antenna projects.

Never say "this is physically not possible", because
tomorrow one might show you, that it IS POSSIBLE.

The successful way goes through understanding and
real world experimenting !

Wishing you a good success in your next project

Felix, HB9ABX