Often the control and instrumentation engineer finds himself/herself faced with the problem of producing a designated complex waveform. Usually his/her simplest approach is to divide the problem into two parts: first, the generation of simple waveshapes and, second, some type of operation on them to achieve the desired final result. If the required waveform is of a sufficiently complex nature, several substages of shaping may be needed. Generation always involves the use of active elements, and although they also perform a function, shaping is frequently effected by the circuit's passive components.
Wave shaping describes the function performed by a wide variety of electronic circuits. For example, a limiter may produce a rectangular output waveform from a sinusoidal input waveform. An integrating circuit converts a rectangular wave to a triangular wave. Linear amplification of voltage or current time functions calls for an increase in amplitude without distortion of waveform and can be regarded as a special case of wave shaping.