Microstrip Antenna Array Design For Mine Microwave Power Transmission

With the development of the Internet of things technology, the wireless sensor network has become an indispensable part of the underground work, sensor nodes use battery power supply, the power supply time is limited and maintenance cost high, a new technology is needed. The microwave power transmitting technology can solve the problem of energy supply properly. Thus proposed the microwave transmission development direct, and studied the characteristics of electromagnetic wave transmission characteristics in underground and the design of antenna array, this study has theoretical and practical significance to solve sensor nodes energy supplement problem.In order to determine the indicators of antenna array, we do some research for undermine electromagnetic wave propagation characteristics. At first, the paper compared waveguide mode and the logarithmic decay model, find that the logarithmic decay model is more suitable for undermine electromagnetic wave propagation. Then collected some experiment data of roadway tunnel size, tunnel wall material and polarization mode, tested the electromagnetic received power in different positions of wireless sensor nodes, recorded the received power in X(horizontal), Y(vertical), Z(vertical) polarization modes. At last, it comes the conclusion of antenna array by analyzed the experimental data: linear polarization, beam concentration, high gain, small areas.According to the analysis of related antenna theory, in this paper we designed an embedded antenna unit has 7.81 dB simulation gain. By using the comprehensive method we determined antenna unit spacing, the number of antenna array and the feed network of mircrostrip antenna. Finally, combined this elements together to consist antenna array. After simulation, the result showed that, the 4×4 mircrostrip antenna array we designed has 20.15 dB gain, E face half power lobe width is15°, H face half power lobe width is 20°, sidelobe level below-10 dB. The fabricated microstrip array antenna is tested in the simulation tunnel, compared dipole antenna, horn antenna and microstrip antenna array, concluded that the microstrip antenna array is more suitable for the energy transmission in the tunnel than the omni-directional antenna. Microstrip array antenna has a small size and light weight, it is easier to install and move.