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A new fully digital Giant Magneto-Impedance (GMI) sensor is presented. The design combines the off-diagonal configuration of the sensitive element with a real-time digital electronic conditioning based on a Software Defined Radio (SDR). Compared to a conventional implementation of these sensors, the proposed design exhibits key advantages. These include firstly the simplicity of obtaining a quasi-linear sensor response around the zero-field point without making use of a bias magnetic field and an offset cancelling device. Secondly, the potential of integration, the flexibility of reconfiguration as well as the low-noise and high-sensitivity are promising features of the developed concept. Noise performance of 1.8 pT/ Hz was obtained in the white noise region. [ABSTRACT FROM AUTHOR]

This paper deals with practical issues and solutions related to the use of the giant magnetoimpedance (GMI) for electrical current measurement. It presents an overview of a full attempt of design and realization of an almost industrial GMI-based current sensor or clamp. The sensor combines dc and ac measurements with the same flexible sensitive element. This paper addresses several practical problems encountered in a real measurement environment. In this context, main attention was paid to the impact of the influence quantities that largely condition the implementation strategies and solutions of the sensor. For the intended industrial application, these influence quantities first include the operating temperature. Its impact on the intrinsic sensor response was investigated in an almost industrial temperature range. Second, bending stress on the sensitive element is another involved influence parameter in the toroidal and flexible structure of the sensor. The effect of this was also characterized. Finally, the third considered influence parameter is the effect of magnetic disturbances. These include the eccentricity of the conductor of interest and the impact of the surrounding magnetic fields such as the earth’s field or fields produced by other conductors in close proximity to the sensor. Different strategies of implementation and solutions, taking into account the impact of influence parameters, were proposed and compared. A sensor prototype was realized, and its first performances were given. [ABSTRACT FROM AUTHOR]

The implementation and the performance of a software-defined radio (SDR) detector for the signal demodulation and processing in off-diagonal GMI sensors are presented. One of the underlying ideas of this SDR is to benefit from the possibility to obtain almost linear and asymmetric characteristics of the off-diagonal component around the zero field. Unlike the commonly used peak detectors, the implemented SDR detector allows retaining this feature, without using any bias field and additional techniques of offset canceling. The key rules for a successful implementation of the SDR detector are given in some details and its potential is addressed. The first performances of the sensor are given and discussed. These include response, sensitivity, and noise as well as dynamic range, linearity, and slew rate. [ABSTRACT FROM PUBLISHER]