Analysis of concentric split ring square reflectarray element for bandwidth enhancement

An analysis of phase variation and phase range of concentric split ring square element for broadband reflectarray antenna is presented in this paper. This element is the combination of a single square element and a ring element where the square element is the modification of the conventional annular ring element which instead of using annul as the hole, this new idea presents a square as the hole in the ring. This will vary the current distribution in the element which will then improve the performance of the bandwidth. The analysis and the design of this reflectarray element is presented based on variable size which operates at the first resonant frequency of 13.44 GHz and at the second resonant frequency of 18.36 GHz. The design procedure and critical parameters consist of phase range and phase slope (or variation) are also discussed. Modifying the current distribution of square ring element, leads to a less steep phase variation and also enhancement on the bandwidth performance (up to 67.6%). The practical phase range is achieved through the use of RF35 as the substrate with the dielectric constant of 3.54 and the thickness of 1.524 mm. CST Microstripes is used as the software tool to get the simulation results.