Design of Ultra High Aperture Efficiency Surface Wave Antenna Array Based on the Three-Dimensional Aperture Principle

To overcome the conflict between limited space and the requirement for high gain antennas, a novel high aperture efficiency antenna array consisting of surface wave end-fire antennas is proposed based on the three-dimensional aperture principle. By introducing longitudinal dimension into the calculation of the regular aperture antenna gain, the two-dimensional aperture principle is expanded into the three-dimensional aperture principle. Meanwhile, the directivity and gain of the array could increase without increasing the aperture area. The aperture efficiency of the array could be more than 100% in this situation. The gain of the surface wave end-fire element antenna is 9.5 dBi. The proposed 3 × 3 square antenna array with the size of 1.5λ × 1.5λ × 2.24λ obtains a gain of 15.3 dBi and its aperture efficiency reaches 120%.