Directivity and sensitivity of high-frequency carrier type thin-film magnetic field sensor

We discuss the directivity and sensitivity of high-frequency carrier type t hin-film magnetic sensor (or so-called MI sensor.) Inductance of the sensor was proportional to cos(3)theta, where theta is an angle between the appli ed magnetic field direction and the length direction of the sensor. If the length of the sensor is bigger than its thickness and width, the intensity of effective magnetic field inside the Magnetic thin film was proportional to H(dc)cos theta, where H-dc is the applied external de field. A high sens itivity of 2 x 10(-4) Oe was obtained when a 140 MHz carrier current was ap plied and the signal was detected by a lock-in amplifier. (C) 2000 Elsevier Science S.A. All rights reserved.