# characteristic impedance

## Definition

### Electronics

- The impedance of a circuit, which when
__connected__to the__output__terminals of a uniform transmission line, makes the__line__appear infinitely long. Under these conditions, the transmission line has no standing waves, and the__ratio__of voltage to__current__at any given frequency is the same at any point of the line. Also called surge impedance. Its__symbol__is Z_{0}.