Effect of azimuth angle and bias field on second harmonic distortion in differentially biased MR heads

Measurement of the azimuth dependence of the second harmonic distortion (SHD) in magnetoresistive (MR) heads is presented. The use of differential biasing and sensing is one method of eliminating SHD by perfect cancellation of distortion signals from two half-elements oppositely biased. However, when some azimuth angle between the MR element and recorded signals is introduced, the SHD rapidly increases due to an imbalance in the input signal strength for each half-element. The effect of bias field and data on single end biased elements is given