On Tue, Oct 20, 2009 at 4:38 AM, Gabriel Paubert <[email protected]> wrote: >> I have done some testing of various passives (mostly 0402) and came to >> the conclusion. I tested both shunt and series capacitors on a 50 ohm >> transmission line with a VNA. What was most interesting to me was that >> the large value capacitors performed better as series coupling caps >> than the small ones. The single layer caps in the 1 to 100 pF range >> frequently had parallel resonances in the 10 to 30 GHz range. Most of >> the multilayer caps (10 nF to 1 uF) performed well to at least 30 GHz. > > And for the shunt case? > > Some manufacturers (ATC, Dielectric Labs) also offer specific broadband > coupling capacitors, did you try them? > > Gabriel
I have some samples of the Dielectric Labs parts, but have not tried any since the cheap MLCC parts work well enough. I can't imagine that the inductance could be much lower. As shunt caps, all 0402 parts have too much series inductance to do much good above a few GHz. The only difference between values seems to be where the series resonance is. Darrell Harmon _______________________________________________ geda-user mailing list [email protected] http://www.seul.org/cgi-bin/mailman/listinfo/geda-user
