Abstract
A new concept of a high-frequency amplitude detector and demodulator for Giant-Magneto-Impedance (GMI) sensors is presented. This concept combines a half wave rectifier, with outstanding capabilities and high speed, and a feedback approach that ensures the amplitude detection with easily adjustable gain. The developed detector is capable of measuring high-frequency and very low amplitude signals without the use of diode-based active rectifiers or analog multipliers. The performances of this detector are addressed throughout the paper. The full circuitry of the design is given, together with a comprehensive theoretical study of the concept and experimental validation. The detector has been used for the amplitude measurement of both single frequency and pulsed signals and for the demodulation of amplitude-modulated signals. It has also been successfully integrated in a GMI sensor prototype. Magnetic field and electrical current measurements in open- and closed-loop of this sensor have also been conducted.
Highlights
Magnetic sensors are widely used in most areas of engineering and industry
The relative complexity of implementation; which requires the use of microcontrollers or Digital Signal Processors (DSP), may limit their use to specific applications where the desired signal-to-noise ratio (SNR) could not be achieved by traditional analog electronic conditioning
The Direct Digital Synthesizer (DDS) voltage output is coupled to a new structure of voltage-to-current converter (v-i) which has been addressed in our recent work [32]
Summary
Magnetic sensors are widely used in most areas of engineering and industry. They are suitable for a large palette of applications ranging from high-density magnetic recording to biomedical applications, non-destructive testing, automotive, space, military, security and scientific research applications [1]. The relative complexity of implementation; which requires the use of microcontrollers or Digital Signal Processors (DSP), may limit their use to specific applications where the desired signal-to-noise ratio (SNR) could not be achieved by traditional analog electronic conditioning This may be the case in high sensitivity GMI sensors where the ultimate SNR is still dominated by the noise of the analog electronics rather than by the intrinsic noise of the sensitive element. The RMS-to-DC converters can address the problem of the diode threshold since they are able to measure signals with amplitudes as low as a few tens of mV with high accuracy [27,30] They are easy to implement and require few components. Compared to the synchronous detection and the SDR demodulation, the new design is obviously justified by the simplicity of implementation This advantage, which is shared by the diode-based detectors and RMS-to-DC converter, is retained. The GMI sensor, which integrates the new developed detector, will be used for magnetic field and electrical current measurements in open- and closed-loop operations
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
