Frequency response measurement in magnetic recording systems employing characteristic M-sequences

By employing characteristic M-sequences, the frequency response function can be obtained by a single pass of the sequences through the system under investigation. These sequences are especially useful in determining the frequency response of digital input/output systems due to their discrete nature. In addition, real-time frequency response measurement can be achieved since characteristic M-sequences possess a wideband, flat gain frequency spectrum with the net phase equals to zero. The magnitude and phase response measurement of two filter systems and several different magnetic tape recording systems are carried out and their results are presented.