Radio reception relies on the medium which determines the propagation characteristics of the electromagnetic fields carrying the information. The permittivity varies greatly depending on the medium, but it remains nearly constant, except when magnetic materials are used. For this reason, magnetic fields, typically affected by permeability, can be utilized in microwave challenging environments. In this paper, a new approach based on the giant magnetoimpedance (GMI) effect is presented. The proposed GMI-based receiver has an effective double-superheterodyne topology, where "effective" means that the receiver actually has a single mixer but appears to have added a virtual mixer due to the GMI effect. The magnetic field-tovoltage conversion ratio (MVCR), the spurious free dynamic range (SFDR) and the receiver sensitivity are characterized, and from these results the optimal operating conditions of the fabricated receiver are obtained. Additionally, wireless digital communication using on-off keying (OOK) is demonstrated and transmitted and received waveforms are compared, with the final demodulation result of the receiver showing that the transmitted digital data are precisely extracted.

Given the interest of researchers for wireless communications in electromagnetic (EM) shadow areas, a magnetic field communication has emerged to overcome RF challenges based on magnetic permeability characteristics. However, the magnetic field communication has the demerit of a short communication range. Considering this limitation, we have proposed the GMI sensor-based field receiver to obtain immunity to low-frequency noise and high sensitivity for extension of communication range in previous studies. Further, this paper designs a magnetic field communication system with a GMI sensorbased receiver including a transmitter. Even though the basic concept of magnetic field communication is taken from previous studies, this study conducts the different realization of the system with transmitter system and communication link. Besides, this paper proposes the experiment of magnetic field communication using a GMI sensor-based system to verify the applicability in the practical environment for the first time. Bit error rate (BER), spurious-free dynamic range (SFDR), and random noise are measured with on-off keying (OOK) communication link to analyze the stability and reliability of the system. The experimental verification and analysis entail the conditions of communication distance and channel medium to mimic practical communication in atmospheric, underwater, and underground environments. A comprehensive analysis of the system design and experimental verification for application in a practical environment show the possibility of the proposed system to realize improving wireless communications in EM shadow areas.

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