WAAS space segment antenna based on EBG superstrate gain enhancement technique

RF and mechanical design considerations for Wide Area Augmentation Service (WAAS) space segment antennas based on the use of an Electromagnetic Band Gap (EBG) superstrate are discussed. This novel antenna configuration has many attractive features such as compactness, low mass and reduced complexity. Two EBG WAAS antenna configurations, one with an array of circular patches and the second one with an array of helices are presented and discussed. Minimum gain and phase center stability specifications determine the array size and the quality factor of the EBG superstrate that can be used in this application. Simulation and measurement results are in good agreement and demonstrate that an EBG antenna concept can meet the requirements of the WAAS antenna application Thermo-mechanical distortion and multipactor margin for the helix array antenna, which are important factors for space qualification of the antenna, are also considered.