Improving output gain of wireless sensor network hardware design for underground applications

The demand using Wireless Sensor Network (WSN) in underground applications increases rapidly. At the present time, almost researches try to adapt current aboveground WSN platforms for underground applications in order to show a better transmission method. Unfortunately, the wireless communication range of WSN in underground applications is very limited because electromagnetic wave, which is used for aboveground wireless communication, is extremely attenuated in underground environment. In this paper, we analyze the theoretical communication limit and propose a hardware circuit increasing the wireless communication range for underground applications. The proposed design increases the range by improving output gain at transmitters. Experiments are performed to determine the actual distance limit. Circuit simulation results are also presented and confirmed that an output gain of wireless sensors is improved.