Theoretical analysis for beam pointing accuracy of stair-planar phased array antenna with tracking beam

In this paper, the stair-planar phased array antenna with tracking beam is introduced and the beam pointing characteristics are theoretically analyzed from numerical simulation. The vehicular antenna was developed as engineering model to provide the satellite internet services in mobile environment. Especially, radiator subarrays of this antenna are arranged like stairs to design for low profile. This structure brings about the pointing error between the main and tracking beams due to the difference of each frequency. To solve this trouble, two treatments using RF cable length compensation and 2/sup nd/ level phase compensation are investigated. In addition, this analytic model of beam steering will help to design and evaluate the antenna beam pattern.