Rotating permanent magnet antenna array for directional communication in pipeline monitoring system

As a novel pipeline monitoring technology, wireless sensor networks (WSN) have the advantages of low power consumption, flexibility, and robustness in aboveground, underground, and underwater pipeline monitoring systems. Using low-frequency (LF) rotating permanent magnet antennas (RPMA) for communications from sensor nodes (SN) to autonomous unmanned vehicles (AUV) has the advantages of low attenuation, low latency, and portable size. However, the communication ranges of different SNs may overlap and information from different SNs should be distinguished. Methods like time-division multiplexing (TDM) and frequency-division multiplexing (FDM) are not suitable in this case. Another way is to form RPMAs into an array so that directional communications from SNs to AUVs can be realized and there is no overlap between SNs. Therefore, this work analyzes and enhances the directivity of linear RPMA arrays in the near-field region. Based on the designed RPMA array prototype, the directional communication is realized at a distance of 5 m across concrete walls. This work paves the way for directional communications from SNs to AUVs in underground pipeline monitoring systems.