A Novel Double-Petal Loop Element for Broadband Reflectarray
In this paper, a reflectarray antenna composed of a combination of double-petal loops of variable size is presented. To evaluate the performance of the designed element, a parametric study is carried out using Ansoft HFSS. For the optimal parametrics, the proposed structure shows an almost linear behavior, while the phase range is in excess of 500°. Then, a prime-focus 77-element reflectarray with this type of element has been designed and implemented. The measured results show that the obtained 1-dBi gain bandwidth of the reflectarray with double-petal loop elements can reach as large as 25% and the highest gain is about 19.3 dBi. Compared with the existing single layer elements (cross and rectangle loop, double rings, etc), microstrip reflectarray with this double-petal loop element can obtain a larger bandwidth.