Re: NEC-LIST: Coupling Query

Warren Rolfe,

You asked about reconciling NEC coupling with network analyzer
measurements. We have done this quite often and the simplest method is
to measure your two port impedances. You can then calculate the
so-called mismatch loss, ML1 and ML2,

num = (vswr - 1);
den = (vswr + 1);
argument = (1 - ((num ./ den).^2));
ML = 10.*log10(argument);

NEC coupling(dB) = IL(network analyzer) - ML1 - ML2

Your network analyzer must clearly be calibrated to the inputs of the
antennas and if the baluns are lossy these (-ve values) must also be
subtracted.

Hope this helps
Andre Fourie

Tel: Intl + 27 11 4030380
Fax: Intl + 27 11 4030381
Website: http://www.poynting.co.za
email: fourie_at_poynting.co.za
Papermail: Dr APC Fourie, PO Box 318, Wits, 2050, South Africa
Received on Tue Nov 17 1998 - 11:46:54 EST