Broadband Gain Enhancement and Frequency Scanning of Fabry–Perot Antenna With Non‐Uniform Partially Reflecting Surface

This paper presents a Fabry–Perot (FP) antenna with broadband gain enhancement and frequency scanning characteristics. Three types of partially reflecting surface (PRS) units with large reflection amplitudes in a wideband make up a non‐uniform PRS. Though the PRS with only the first type of units can broadly improve the antenna's gain, one steep gain stopband exists, dividing the 3 dB gain bandwidth. Therefore, some units are adjusted to the other two types of units to remove the gain stopband and realize wideband gain enhancement. Moreover, the FP antenna also realizes frequency scanning due to the phase difference of the incident waves to PRS that varies with frequencies. The measured results show that the FP antenna has a 10 dB impedance bandwidth of 6.7–14.7 GHz (74.8%) and a 3 dB gain bandwidth of 6.5–12.9 GHz (66%) with a peak gain of 11.6 dBi at 8.5 GHz. The antenna also has a large gain‐bandwidth product per unit area (GBP/A) of about 640 with a compact structure. In 6.5–12.9 GHz, the FP antenna offers a relatively large unidirectional beam scanning range from 5° to 44°.