A highly sensitive high frequency carrier-type magnetic field sensor based on the giant magnetoimpedance effect has been developed. It has been combined with a high frequency carrier suppressing circuit to reduce carrier phase noise dramatically. Highly sensitive magnetic field resolution of 8.8 10 7 Oe (8.8 10 11 ) was demonstrated.Index Terms-Carrier suppression, giant magnetoimpedance, high frequency carrier, magnetic field sensor, phase noise.