Wideband Log-Periodic Endfire Antenna With Dielectric Lens for X-Band Applications

In this letter, a wideband, high-gain log-periodic endfire antenna using dielectric lens is proposed. The design of the antenna is based on the idea of log-periodic antenna, and the wire dipole elements in log-periodic antenna are replaced by half bowtie dipole elements to achieve a wider impedance bandwidth. The broadband performance of the antenna is improved by loading split-ring resonators at the end of the antenna. The measurement results show that the working bandwidth of the whole antenna is 7.18 GHz to 12.55 GHz, and the gain of the antenna with the dielectric lens loaded in the end is about 11.1 dBi to 16.0 dBi in the whole working band, which is about 4.5 dB to 7.5 dB higher than that without the lens loaded. With a total size of 3.52λ<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</sub> × 2.67λ<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</sub> × 2.67λ<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</sub> (λ<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</sub> is the free space wavelength at the center frequency), the bandwidth covers the entire X band, making it suitable for numerous low-Earth-orbit satellite ground stations. Its broad frequency coverage characteristics (8 GHz to 12 GHz) can support multisatellite collaborative communication and help alleviate the problem of spectrum fragmentation.