Research On Electrical Characteristics Of Leaky Coaxial Cable (LCX) Used For Radio Communication In Confined Areas

Leaky Coaxial Cable (LCX) is widely used in radio communications in confined areas such as mines, subways, tunnels and buildings, and the research on its electrical characteristics is becoming a hotspot increasingly.Beginning with the structure of leaky coaxial cable (LCX), the paper introduces the geometrical and physical parameters. Then, it discusses the radiation principle by the structure and analyses its radiation modes. Also, it calculates the radiated field in free space by the field distribution on the slots of the outer conductor using the cylinder Fourier Transformation. Further, it analyses the solution of radiated field in unfree space where reflection exists and discusses the effect of location of LCX on the radiated field. Then, it proposes some important characteristic indexes of LCX, and discusses the basic theory and referent problems when designing the indexes of frequency band, standing wave ratio, coupling loss and transmission attenuation. Afterwards, it designs the electrical characteristic indexes of LCX synthetically. Finally, it introduces the concrete applications of LCX in confined areas such as subways, highway tunnels and buildings respectively, compares the difference of the coverage performance of antenna radiation and LCX radiation and proposes the schemes to achieve radio communication.