Re: NEC-LIST: How to get actual far field value??

From: Madjid BOUKRI <mboukri_at_email.domain.hidden>
Date: Tue, 23 Sep 1997 10:59:12 -0400

Hi Ed,

Interesting problem !!!

NEC4WIN has a Mininec engine and does not recompute the Far Field
based on the mismatch.

According to theory the gain of a very short antenna is just a
fraction of dBs below the full size quarter wave. We all know that
this is not true in practice due to increased losses in wires and
matching network, but in your case is it really a problem?

In practice you will have to match somehow the antenna to a
certain impedance (unless you are using milliwatts and an
unmatched system).

To get more realistic Far Field results you should add a matching coil
and losses at the base of your short radiator as a serial
resistor. This will immediatly bring your antenna in the real world
with gain in the minus dBs range and fields will be reduced
accordingly.

Regards,

Madjid BOUKRI
Received on Thu Sep 25 1997 - 10:38:05 EDT

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