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Angle sensors operating on optical,electric,and magnetic principles are extensively used as transducers in all kinds of position and speed control applications.A novel minitype angle sensor consisting of a specified gear,a magnet,and a tunnel magnetoresistance(TMR)magnetic sensor has been proposed in this paper.The gear is made up with Permalloy,which is constituted the magnetic circuit with the magnet.The TMR magnetic sensor is placed between the gear and the magntic to detective the magnetic field.With the rotation of the gear,the magnet applies an ac magnetic field to the TMR magnetic sensor.The output waveform of the proposed angle sensor has a good sine property,so the angle position can be measured by high-precision techniques for amplitude and phase discrimination.And the angle speed is directly proportional to the waveform's frequency.At the meanwhile,if the gear appears geometry eccentricity,the output waveform is modulated by a low frequency signal.Through picking up the amplitude of the low frequency signal,the eccentricity of rotating pieces can be determined.As the low frequency signal is related with the gear's absolute position,so according to the amplitudes or phases of the output waveform and the low frequency signal,the absolute position of the rotating pieces can be measured with advantages in accuracy and resolution.