Directional coupled sectorial loops antenna for Ground Penetrating Radars applications

In this paper, a directional UWB antenna based on the concept of coupled sectorial loops antenna (CSLA) is presented [2] [3]. The proposed antenna uses CSLA backed by a short cylindrical cavity with a modal suppressing septum to accomplish unidirectional radiation pattern. Bandwidth enhancement is accomplished by a pair of peripheral slots and a stacked CSLA configuration. sensitivity study is carried out to optimize the geometrical parameters of the antenna in order to achieve the maximum bandwidth and uniform radiation pattern. Through this optimization, this antenna has a VSWR lower than 2.5 across a 2.7:1 frequency range without the use of absorbing foams or lossy elements. The dimension of this antenna is approximately 0.5 λο at the lowest frequency of operation.