Manhole cover type omnidirectional antenna

A manhole cover type omnidirectional antenna comprising:

• a manhole cover installed in a manhole in the Earth's surface;
• a main body installed in a cavity of an upper surface of the manhole cover and configured to convert an electrical signal into an electromagnetic wave to wirelessly communicate with a gateway separated from the manhole cover;
• and
• a radome inserted into the cavity to cover the main body,
• wherein the main body includes:
• a lower plate and an upper plate parallel to the lower plate,
• a plurality of shorting strips connecting the upper plate and the lower plate, the plurality of shorting strips connected to the upper plate in a length-wise direction;
• and
• a plurality of slots formed in the upper plate to be spaced apart from the shorting strips, the plurality of slots being symmetrically disposed in a direction perpendicular to the length-wise direction of the plurality of shorting strips.