Improvement of sensitivity using carrier suppression technique in high frequency carrier type thin-film magnetic field sensor

Summary form only given. This paper demonstrates a high frequency carrier type thin-film magnetic field sensor (or so-called GMI sensor) with the ac field sensitivity of 9/spl times/10-12 T. The sensitivity achieved is well competitive with the high temperature SQUID devices. This has been realized by reducing the phase noise floor down below the thermal noise of -174 dBm at room temperature through the carrier suppression technique. A new idea of sensitive dc field detection is also proposed.