A Fabry–Perot Resonator Antenna With Wideband Gain Enhancement and Frequency Scanning Characteristics

A novel Fabry–Perot resonator antenna (FPRA) with wideband gain enhancement and frequency scanning characteristics is proposed. The gain of original monopole-type radiation patch exhibits a significant fluctuation in the operating frequency range, resulting in a narrow 3 dB gain bandwidth. Hence, two types of partially reflecting surface (PRS) units with appropriate reflection coefficients that can compensate the gain fluctuation of original radiation patch are designed. These PRS units improve the gain amplitude and flatness simultaneously, which would bring a much larger gain-bandwidth product (GBP). Meanwhile, the proposed FPRA also has a frequency scanning property due to the phase difference of adjacent incident waves to PRS that varies with the operating frequency. The measured results indicate that the proposed FPRA has a 10 dB impedance bandwidth of 7.1 GHz to 25.5 GHz (112.9%) and a 3 dB gain bandwidth of 7.42 GHz to 23.12 GHz (102.8%). It has a maximum gain of 15.73 dBi at 13.5 GHz and a large GBP per unit area of 1764.4, realized with a simple and compact structure. In 7.42 GHz to 13.9 GHz, it also illustrates a frequency scanning angle of approximately 0$^{\circ }$–$43^{\circ }$.