Circular-polarized proximity-fed tip-truncated triangular switchable array for land vehicle mobile system

This paper proposes a compact, circularly polarized (CP), tip-truncated, triangular patch array developed for a land vehicle mobile system for mobile satellite communications. The array is constructed by three patches so that its beam pattern can be switched in three 120°-coverage beams in the azimuth plane with minimum gain requirement at a fixed point of the elevation angle. With this pattern, data communications with a large geostationary satellite can be achieved. The targeted gain is set to be 5 dBic at 48^° of the looking angle from the satellite in the Kanto area. The patches are fed with a proximity feed technique because of its simplicity and easier installation on the vehicle. The array performance is numerically analyzed with the method of moment to clarify the array characteristics. Measurement results are provided to validate the simulated results. The results show that the array meets the specifications at the targeted looking angle of 48° when the gain is more than 5-dBic for each three-selectable beams in the azimuth plane.