A C-Band Flat Lens Antenna With Double-Ring Slot Elements

A novel flat lens antenna using double-ring slot element is presented. Compared to those conventional high-gain antennas, the proposed lens antenna can realize greater flexibility in the installation with less manufacturing complexity. A prime-focus 49-element prototype lens antenna using the proposed elements has been fabricated and measured. The highest measured gain is 16.7 dBi at the center frequency of 6 GHz, and a relative bandwidth of 15% is achieved within 3-dB gain variations. All experimental results demonstrate that the proposed lens antenna can be used as an optimum airborne antenna in the future.