Low-Profile Substrate-Integrated Wideband Monopole Antennas

Low-profile monopoles operating over a wide bandwidth are highly desirable for integration into various metallic/conductive platforms, e.g. on vehicle roofs. A simple realization of omnidirectional radiation patterns is offered by center-fed shorted patch antennas, which have been first proposed in the 1950's [1]. This type of antenna has been revisited many times since then and recent designs achieve high performance combining wide bandwidth of operation and ultra-low profile. The general principle of operation of low-profile monopoles can be generally interpreted as physical realization of a magnetic current loop [2].