Fig. 1. Schematic models of PIFEPA at the conditions of low-power and high-power incident waves

Fig. 2. Structural diagram of PIFEPA

Fig. 3. Equivalent circuit model of PIFA

Fig. 4. Equivalent circuit model of PIFEPA

Fig. 5. Equivalent circuit model of PIN diode

Fig. 6. Variation of reflection coefficients of PIFEPA with the number of vias

Fig. 7. Variation of reflection coefficients of ESA with the U-shape branch length

Fig. 8. Simulation result of reflection coefficient with 4 vias and 15 mm U-shaped branch length

Fig. 9. Simulated radiation patterns of PIFEPA with diodes on-state and off-state

Fig. 10. Prototype of the antenna

Fig. 11. Test environment and equipment

Fig. 12. Simulated and measured reflection coefficients

Fig. 13. Simulated and measured radiation patterns of PIFEPA

Fig. 14. Measured received power of the EPA versus the input power