Substrate integrated waveguide cavity-backed log-periodic slot antenna for Ku and K band applications

In this article, a novel substrate integrated waveguide (SIW) is used to design multifrequency cavity-backed log-periodic slot antenna. The proposed design has three layers of cavity-backed structure namely feeding SIW, resonant SIW, and log-periodic slot SIW in order to achieve low loss, high gain, and easy integration with high-frequency components. The proposed structure also includes an inductive window slot to couple the energy from feeding SIW to resonant cavity. The experimental results shows that 10-dB impedance bandwidth of 870 MHz (7.9%), 390 MHz (2.7%), 410 MHz (2.5%), 310 MHz (3.9%), and 420 MHz (2.2%) are obtained at resonant frequencies 11.25 GHz, 14.25 GHz, 15.95 GHz, 16.9 GHz, and 19.15 GHz, respectively. Also, a realized gain of around 18.24 dB is obtained at the bore sight direction. Moreover, the simulated and experimented results are in good agreement and make the antenna more suitable for Ku and K band applications.