Giant Magnetoimpedance Receiver With a Double-Superheterodyne Topology for Magnetic Communication

Kibeom Kim,Seunghun Ryu,Hyun-Joon Lee,In-Kui Cho,Jaewoo Lee,Seungyoung Ahn,Jang-Yeol Kim

doi:10.1109/access.2021.3085603

Abstract

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-to-voltage 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.

Highlights

In harsh wireless communication environments such as underground or underwater environments, the conventional technique of using microwaves faces many challenges, including path loss, multi-path fading and signal propagation delays due to the presence of soil, rock and water, which are composed of various components [1]–[3]
With a non-conventional medium, communication based on magnetic induction (MI) is a good alternative when attempting to address the challenges of microwave-based communication
This paper presents a system analysis and discusses the principle of the operation of a giant magnetoimpedance (GMI)-based receiver with the double conversion superheterodyne topology

Summary

INTRODUCTION

In harsh wireless communication environments such as underground or underwater environments, the conventional technique of using microwaves faces many challenges, including path loss, multi-path fading and signal propagation delays due to the presence of soil, rock and water, which are composed of various components [1]–[3]. SFDR from the power spectrum measurement using an external magnetic field strength of 116.2nT in the linear region (see Fig. 5) at fext=60 kHz. a Helmholtz coil with N = 90 turns and R = 150mm generates an external magnetic field with fext ranging from 1kHz to 100 kHz. Here, fGMI and voltage driving the GMI wire are 5MHz and 1.63V, respectively. When comparing the characteristics at fext = 60kHz and 100kHz, the SFDR difference is 2.5dB, but at 60kHz the MVCR is approximately 28 times better, detecting fine magnetic field strengths as low as 1/28 times the original level These results show that the optimal communication frequency of the receiver is 60KHz

OOK WIRELESS COMMUNICATION RESULT

CONCLUSION