Cavity backed sinuous antenna for IoT applications

In this paper, we discuss the design and optimization of a four arms non-conventional planar sinuous antenna in a cavity backed configuration. The design of the whole antenna system was carried out with the aim to provide unidirectional radiation pattern and to optimize the antenna performance for ultrawideband (UWB) IoT applications. The antenna arms shape was modified to improve the antenna performance in terms of efficiency, radiation pattern and to gain flatness in a wide frequency range. To mitigate the deleterious effects due to the resonances, a special cavity shape and a dispersive broadband absorber with a radial-dependent thickness were designed. Moreover, different miniaturization techniques were implemented to reduce the antenna size. The designed low-profile antenna can operate in the frequency range from 1.5 GHz to 18 GHz exhibiting a maximum gain of about 5 dB as well as it has an effective antenna diameter of 6 cm.