I have a fast (10s of ps edges) pulse that I want to AC couple. The bias on the source side will be 15 volts, and the load is 50 ohms to ground. I need at least 1 uF to minimized droop, preferably more. The
50 ohm trace is 45 mils wide.The 0204 fits the trace nicely but doesn't have enough capacitance at
15 volts. The 0603 is too small too, and has more inductance than I want. 0306 doesn't have enough capacitance either.A 10 uF 16V 0508 kinda works. It will have roughly 1.5 uF left at 15 volts. It does bulge out a bit from the trace width, which adds capacitance and maybe a little inductance. I guess I could teardrop the traces and then cut away a little ground plane to correct for the extra capacitance. That's hard to calculate.
Any suggestions on how to do fast-edge-long-tau AC coupling on microstrip?