Efficiency enhancement consideration for a low-frequency FR-ORA array

A design of conjugated resistive frequency selective surfaces with capacitively coupled phased Fractal Octagonal Rings Array (FR-ORA) has been proposed for low-frequency aperture array radio astronomy. The presence of the resistive loading has expanded the bandwidth of the array to a ratio of 8:1, but at the expense of its radiation efficiency performance (at the high end of its operating frequency). To alleviate the radiation losses, a design consideration to maximize the sensitivity of the element array is presented in this communication. The intention was implemented by drawing the radiation losses away from the substrate loading. Subsequently, a clear demonstration of the new figure FR-ORA array system sensitivity is analyzed to meet the required sensitivity for the Square Kilometer Array (SKA).