ON-BOARD LARGE MESH ANTENNA REFLECTOR WITH HIGH SURFACE ACCURACY

An increase in the size of on-board antenna reflectors is a key techno logy in providing economical services by miniaturized portable equipme nt in future mobile satellite communication systems. In practice, a me sh antenna can be used as the on-board antenna. However, since the ref lector surface of this antenna is supported by the cable and the mesh, and its size is larger, the surface is subject to larger thermal defo rmation in orbit than is the solid antenna reflector. Conventional com pensation methods such as passive thermal control or rotation of the a ntenna reflector cannot maintain the required antenna performances. Va rious methods have been reported to compensate for the deterioration o f antenna performance by thermal deformation. This paper describes a s tatic shape control system for a 10-m diameter antenna which actively compensates for the deformation by using a shape-measuring sensor and shape-compensation actuator. The configuration of the sensor and the e xperimental results by a functional model are described to confirm the design validity. The shape-compensation method by the actuator was co nfirmed to be useful in achieving a required surface accuracy.