0-9 | A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z
A wave that has two significant conditions, i.e., two levels of amplitude, that change from one condition to the other in a relatively short time compared to the wavelength. Note: When the instantaneous amplitude is plotted versus time or distance, the waveform has a rectangular shape. [From Weik '89]