Most microwave hardware is specified to run in a fifty ohm system. Why was this standard chosen?
50 ohms is a great compromise between power handling and low loss, for air-dielectric coax.
The arithmetic mean between 30 ohms (best power handling) and 77 ohms (lowest loss) is 53.5, the geometric mean is 48 ohms. Thus the choice of 50 ohms is a compromise between power handling capability and signal loss per unit length, for air dielectric.
50 ohms is a great compromise between power handling and low loss, for air-dielectric coax.
The arithmetic mean between 30 ohms (best power handling) and 77 ohms (lowest loss) is 53.5, the geometric mean is 48 ohms. Thus the choice of 50 ohms is a compromise between power handling capability and signal loss per unit length, for air dielectric.