"Dave (from the UK)"
wrote in message ...
Wimpie wrote:

Hi Dave,

Hi Wim

Whether or not the formula is applicable, depends on many factors as
mentioned in my previous posting.

For a broadside array, the formula holds with same accuracy as for
continuous aperture antennas. In my antenna courses I use the
broadside array approach to derive the 2B^2/lambda formula.

My situation is very odd. As I said at the start, this is not an amateur
antenna.

The array of "antennas" are not designed to work as one nice antennas, but
are an essentially random(ish) collection of radiating centres. (However,
they are all energised from the same signal source). So they can be
considered like a phased array, as they are regularly spaced all in one
long line.

Hence my original diagram

A---A---A---A---A---A---A---A---A---A

accurately describes the situation. Each "A" is an antenna. The amplitude
and phase can be arbitrary.

I do *not* want them to behave as a nice phased array with decent gain and
low side-lobes! Each antennas is radiating an *unwanted* signal. But the
fact remains that the gain could conceivably be high under some
circumstances, which would create interference.

Hence I need to test this.

I would reserve the term "far field distance" for that distance where
the complete radiation pattern does not change with measuring
distance. In that case, the 2B^2/lambda formula is a good rule of
thumb.

In this case, I am interested in any direction. The direction of the main
lobe will be essentially random.

--
Dave (from the UK)


Hi Dave

I'm curious about two things.

1 - Do you intend to actually make and record measurements of the
radiated field, or do you want to determine the minimum distance at which
the measurements can be made?
2 - What prevents the use of a computer modeling program to predict the
pattern?

Jerry