Input and output impedance is an important property of complex electronic components. Is it possible to physically measure them like we measure resistance?
Is it possible to measure it for BJT based transistor amplifiers and FET based transistor amplifiers? Also, can the same be done for complex ICs like FPGAs and microprocessors and PHY chips?
Related to this is the source of impedance in complex circuits, i.e what makes up the internal and external impedance. For high speed design we like to have matched impedance to prevent high speed effects in circuit operation. Usually this means making the signal track on PCB a 50 ohm trace and possibly use termination resistors also. A signal going into the input of the IC however has to travel on the PCB track, then through the pin on the package of the IC, through the bonding wire and then into pad and into the input buffer on the die inside the IC package. Do all these different components connected together have 50 ohm impedance each?