Development of Deployment Mechanisms for SAR Antennas

Deployment mechanisms are wildly used in space-bone synthetic aperture radar (SAR). The research status of spacecraft deployment mechanism for planar array SAR is discussed. The common deployment mechanisms can be divided into two different concepts, a hinge-only concept and an extendable support structure concept, and it is pointed out that the deployment mechanism is the main factor that determines the performances of SAR antennas such as pointing accuracy, surface planeness error and thermal stability. The characteristics of two types of planar array SAR deployment mechanisms are analyzed. It is pointed out that the hinge-only antennas are suitable for the occasions with short deployment length and small number of antenna panels, while the extendable support structure antennas can achieve the requirements of higher accuracy, which is suitable for large-size antennas. The key technologies for high-precision deployable SAR antennas are proposed. It is beneficial for hinge-only antennas to develop hinges with a high repeatability precision and high stiffness locking devices. Locking sequence design of the hinges is an approach for avoiding the kinematic singularity of the ESS deployment.