[Antennas] Re: Hairpin monopoles

Thu, 8 May 2003 16:32:15 -0700 (PDT)

--- James Duffer <[email protected]> wrote:
> 
> 
> 
> >From: Wes Stewart <[email protected]>
> >To: James Duffer <[email protected]>,
> [email protected]
> >Subject: Re: [Antennas] Re: Hairpin monopoles
> >Date: Wed, 7 May 2003 17:10:50 -0700 (PDT)
> >
> >
> >--- James Duffer <[email protected]> wrote:
> >[snip]
> >
> >George's explanation is of course right on.
> >
> > >
> > > An interesting analogy but leaves some
> questions.
> > > If the transmission line
> > > is terminated in a load that is equal to the
> > > transmission lines
> > > characteristic impedance, then what has
> frequency
> > > got to do with
> > > characteristic impedance????  The charateristic
> > > impedance is dependent on
> > > the physcial construction
> > > conductor diameter and distance of the
> conductors.
> >
> >Characteristic impedance is dependent on R, L and C
> >per unit length.  R, L and sometimes C are
> frequency
> >dependent.
> 
> Which is dependent on the physical construction of
> the transmission line.  
> Refer to the formulas for Zo of parallel or coaxial
> lines (Zo= 276 Log 2S/d 
> where S is center to center distance between the
> conducior and d is diameter 
> of conductor[same units], Zo= 138 log (b/a) where b
> is inside diameter of 
> outer conductor and a is outside diameter of inner
> conductor.
> 
> Wouldn't manufacturers of coaxial cable state that
> the characteristic 
> impedance Zo is for example 50 Ohms at 100 Mhz if it
> was indeed dependent on 
> operating frequency.  Sorry but I am from Missouri
> and you have to "show 
> me".

Not me.  I'm lettin' George do it :)

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