Design Formulas for Diode Detectors

Different types of linear rectifiers are defined, and the required properties of linear rectification are outlined. The envelope-type of rectifier is preferred as having greatest efficiency. The ideal diode for this type is defined and its behavior in various circuits is outlined. Formulas are given which enable fairly accurate prediction of performance, especially of such factors as the maximum coefficient of inward modulation which is subject to linear rectification, and the amount of distortion caused by the clipping of the peaks representing unity inward modulation. The formulas indicate desirable relations in terms of the admittance of input and output circuits. It is pointed out that a diode rectifier, under certain conditions, has the effect of shifting along the frequency axis, the admittance curve of the input or output circuit, in a manner similar to the frequency-changing operation on the signal. There are described the effects of practical limitations, such as the departure of the diode from the ideal. Practical examples of circuit design are given.