On Apr 9, 2:59 pm, Owen Duffy wrote:
...
Hi Tom,

Warning bells sound to me when applications call for reactors fabricated
from TL sections. Not to say that are always bad, but they aren't always
good, and they bear examination.

....

:-) Yes, indeed. I just this afternoon fabricated a 500MHz LPF that
I wanted to give about 40dB attenuation up to several GHz. My design
was a 5th order elliptical, so I had two parallel tanks for the series
paths and three shunt capacitors. Because the coils (10nH and 15nH)
are so small, I though about using a shorted stub instead, but then
realized that my shorted stub would look like a short when it was 1/2
wave long, not a good thing to have as a series element at a frequency
you want to block. Probably would have worked OK since the two stubs
were different and wouldn't have the same resonance frequency; and by
the time you reached that freq., the shunt caps would be pretty
effective on their own. Anyway, it works fine with tiny coils. Thank
goodness for good microscopes.

Cheers,
Tom