Symmetrical full-wave rectifier

Active rectifiers often consist of an op amp circuit with diodes in the feedback loop. Such traditional arrangements work very well in many applications, but the diodes introduce, by definition, non-linearity. However, the flaw so introduced is compensated adequately if the open-loop amplification of the op amps is sufficiently high. This is well and good at low frequencies, but the open-loop gain of op amps drops appreciably at high frequencies. This results in insufficient compensation of the the non-linearity introduced by the diodes, which gives rise to distortion.