Re: NEC-LIST: phasing networks on collinear arrays

Paul Gili,

You asked:

> How does one model the inductive- looking section commonly used on a
> cellular phone type antenna? It is my understanding that this
> circuit element provides a current reversal to obtain in-phase
> currents on adjacent half-wave sections of the antenna wire when
> driven at one end against a ground plane. Without the 180 degree
> phase shift, the half waves would be in phase opposition thereby
> causing a multi-lobed pattern. A simple series inductance would not
> seem to perform this function.

We have modelled it before as parallel LC loads distributed over a few
segments. This is in fact what happens in practice to give the 180
degree phase shift. Each turn capacitively couples to the adjacent one
and also contributes inductance.

Regards Andre.
 
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Received on Thu Nov 26 1998 - 10:37:48 EST