A Novel Analysis of FM Discriminators by Taylor´s Expansion

The theory of FM discriminators is presented by expanding its transfer function into Taylor´s series, and the application of the results to the typical FM discriminators (slope discriminator, Travis discriminator, Foster-Seeley discriminator, and line discriminator) is added. The output signal of the FM discriminator expressed by Taylor´s expansion shows the clear relationship between the fundamental and the harmonics. The design equations obtained from this analysis enable a designer to construct FM discriminators which will provide a desired low distortion performance.