Conical Beam Compact Antenna for Manholes for IoT Applications in Smart Cities

This paper presents a multilayered antenna solution designed for integration into manhole covers. The proposed antenna features a multilayered structure with no air gaps, ensuring mechanical feasibility in this environment. An aperture is created in the manhole cover to accommodate the antenna, which is fed by a coaxial feed at the center of the structure. The design provides an omnidirectional conical beam radiation pattern, enabling extended coverage. The antenna operates at 860 MHz, with a bandwidth ranging from 850 MHz to 870 MHz, making it suitable for LoRa-based IoT applications.