A low-profile, vertically-polarized, compact, ultra-wideband antenna with a 10∶1 bandwidth

A compact, very low-profile ultra-wideband antenna is presented. The antenna has consistent monopole-like, radiation characteristics over a 10:1 bandwidth. This antenna consists of two main radiators where one radiator is a smaller scaled version of the other one. Each radiator has two parallel loops in the shape of a bent diamond connected to the ground plane at their ends. A properly designed feed network is used to feed the larger antenna at lower frequencies while feeding the smaller one at higher frequencies to improve the consistency of the radiation characteristics of the system over a very broad bandwidth. The proposed antenna has electrical dimensions of 0.24λ_min×0.24λ_min×0.042λ_min at its lowest frequency of operation and demonstrates monopole-like radiation characteristics over roughly a 10:1 bandwidth.