Fig. 1. Simulation model of antenna

Fig. 2. Curve of voltage standing wave ratio (VSWR)

Fig. 3. Curve of axial ratio

Fig. 4. Radiation pattern

Fig. 5. Irradiation waveform of HPM-NS

Fig. 6. Voltage of antenna port under HPM-NS

Fig. 7. Irradiation waveform of HPM-UWS

Fig. 8. Voltage of antenna port under HPM-UWS

Fig. 9. Overall design block diagram of antenna protection

Fig. 10. Equivalent circuit of small signal

Fig. 11. Transient circuit

Fig. 12. Output voltages of the protection circuit

Fig. 13. Test curve of insertion loss

Fig. 14. Injection test system

Fig. 15. BDS/GPS antenna against HPM