Fig. 1. Structure diagram of the antenna main radiation unit

Fig. 2. Structural schematic diagram of microstrip Yagi antenna

Fig. 3. Simulated S₁₁ curve of microstrip Yagi antenna

Fig. 4. Curve of microstrip Yagi antenna gain vs frequency

Fig. 5. Composition and installation diagram of phased array antenna system

Fig. 6. Cross section diagram of railway single-hole and double-track tunnel

Fig. 7. Phase optimized flow chart based on the tunnel environment electromagnetic simulation model

Fig. 8. Electric field intensity distribution at locations A and B of train in tunnel