Can someone point me to information on how to design a lumped delay
>line?
>
>Thanks!
>
> ...Jim Thompson
The simple way is just a string of Ls and Cs.
in--------+---L-----+----L----+----L----+---------out | | | | | | | | C/2 C C C/2 | | | | | | | | | | | | gnd gnd gnd gnd
where
Zo = sqrt(L/C)
Fc = 1/(PI * sqrt(LC))
Td = N * sqrt(LC)
There are fancier formulations, like bridged-tees and such, for specific applications. See the Williams filter book.
The nasty part is that the number of sections explodes as (I recall) the square of the delay/risetime ratio. I have a Basic program that does that math and such.
These things ring, too.
John