On 22 abr, 12:25, "Dave (from the UK)" see-my-signat...@southminster-
branch-line.org.uk wrote:
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
[all text deleted]

Hi Dave,



I don't know what you are going to do with the array. As long as you
understand how a radiation pattern (whether within or outside the far
field distance) can be calculated based on the array elements, you
should be able to find a comfortable distance. I think references to
scientific documents will not help you any further, maybe a physics
book on electromagnetism or a specialized book on beam forming
antennas may help you.

If your organization is not able to do this in-house, you might hire
an expert.

Best regards,

Wim
PA3DJS