The Exploration Of Cooperative Magnetic Antenna Model Of The Wireless Through-the-Earth Communication

China has abundant coal and mineral resources,although the rapid development of green scenery energy has reduced the demand for coal,it still occupies a large proportion.However,the occurrence of mine disaster brought us great harm,if we can achieve timely and effective communication and take corresponding measures when the accident happened,the damage and loss of property will be greatly reduced.It is difficult to lay the stable and effective communication line in the stratum and has poor ability to resist disaster,so it cannot be effective.Traditional single antenna communication system is affected by complex stratum and transmission efficiency is low and weak after long distance attenuation loss.Large size antenna cannot be installed in underground tunnels to improve the reliability of system.Therefore,studying and solving these problems will greatly help to improve the efficiency of mine safety production and establish the highly efficient wireless communication system.The paper proposes the application of cooperative antenna ground penetrating communication system in mines for emergency communications and daily production based on the detailed analysis of the development status andtheoretical basis of mine wireless communication,it can ensure efficient transmission of signal and solve space and power constraints.In order to receive the maximum signal strength,we optimize the arrangement of cooperative antenna layout.The main work is:The paper establishes the equivalent circuit model of magnetic induction communication based on the relevant principle of wireless communication system.Aiming at the conditions of narrow underground space and limited power and other conditions,the characteristics of cooperative communication are discussed based on the radiation theory of magnetic dipoles in free space.The structural characterisation and electromagnetic interference of earth channel are discussed,the influence of different parameters on the communication system is studied by calculating the path attenuation and loss of magnetically induced communication in the process of formation propagation.The directivity characteristics of multiple antennas are analyzed based on the theory of antenna array system.The impedance matrix method is applied to the calculation of the mutual coupling coefficient of the array antenna,and the mutual impedances of different arrangement modes are compared to study the effect of the mutual coupling effect on the cooperative communication.The arrangement layout of cooperative antenna is designed and optimized.The collaborative magnetic antenna model for mines is established by using FEKO7.0 based on MoM Method Theory.The comparison of the magnetic field data between cooperative antenna system and single antenna system in the threelayer geological model shows that cooperative antenna system can increase the magnetic field intensity by 2.13 times,the transmission distance is also greatly improved.The array model of the antenna at different spacings and placement modes is established,and the optimal layout of two antennas is analyzed.The optimized model can increase magnetic field strength by 28 times.The influence of different environmental conditions on the distribution of ground magnetic field is discussed in detail.The conclusion shows that it is feasible to apply the cooperative antenna scheme to mine communication.The cooperative communication technology produces different signal paths which can effectively resist the attenuation and loss of the lower path of mine,and bringing the obvious channel gain.The distribution of environment and strata in different regions is different,and the system can be optimized according to actual needs.The research result of this paper has certain guiding significance for realizing the signal transmission between ground and underground and VLF communication technology,about the research of collaborative communications and optimized layout can also be extended to areas such as underwater communications,underground personnel and equipment positioning,and tunnel,as well as theoretical and practical values that can be used for reference.