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Date: Sun, 8 Jun 2025 11:41:19 -0400
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Subject: Re: transmission line z
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On 6/8/2025 11:39 AM, Bill Sloman wrote:
> On 9/06/2025 12:58 am, john larkin wrote:
>> Suppose you have a slab of FR4 with copper on both sides, standard
>> ebay stuff. Now shear off a long thin slice. That's a balanced
>> transmission line.
>>
>> air
>> __________________ copper
>> .........................................fr4
>> __________________ copper
>>
>> air
>>
>>
>>
>> What's that called?
>>
>> Does anyone know of a calculator that handles this case?
> 
> Neither of my transmission line textbooks say anything about that. It's 
> clearly a kind of transmission line, but presumably not a useful one - 
> it's going to be dispersive, just like microstrip. If it was useful you 
> would presumably be able to buy reels of it.
> 

Used that way it's called a "parallel plate line" and the essential 
characteristics for ye olde Telegrapher's Equation are given in Pozar:

<https://imgur.com/a/gAbKJgk>