As I know, high speed transceivers always use a 0.1uF or 0.01uF capacitor for AC-coupling.
Tx--->capacity------------------->Rx
|
end resistor
Capacitor and end resistor are a high-pass filter.
If end resistor is 50 ohm.
I calculate bandwidth with $$ f = \frac{1}{2 \pi R C} $$ if \$C = 0.1\mathrm{\mu F}\$, then \$f = 31.847\mathrm{k Hz}\$
if \$C = 0.01\mathrm{\mu F}\$, then \$f = 318.47\mathrm{k Hz}\$
But I always see 0.1uF and 0.01uF both used in the 1GHz, even 10GHz circuit.
As I calculated above, bandwidth should not enough.
I'm confused.
f1
tof2
. The bandwidth isf2-f1
. For bands that start at DC, the bandwitdh would bef2-0Hz=f2
. But you need to make certain what your band boundaries are to calculate a bandwidth. If there's no upper bound (like here), the filter has infinite bandwitdh. \$\endgroup\$