Novel phased array antenna structure design

Phased array antennas for space-based radar (e.g., RadarSat) are typically constructed of flat honeycomb panels with attached radar transmit/receive modules and associated electronics, wiring and waveguides. These panels are then mounted to a deep deployable truss structure. Technology advancements in the packaging of radar electronics have yielded lightweight, thin, flexible sheets of integrated phased array transmit/receive modules and associated support electronics. New structures to support these sheets are required to take advantage of their reduced weight and volume, to enable lighter, larger, and more compactly stowable space antennas. A concept for such a structure is described in this paper. A basic description of the space-based radar design is provided, and requirements for the antenna structure are defined. A design of a substructure that supports the electronic sheets is presented, which is based on a lightweight frame and grid-work of composite materials. This design is shown to permit attachment of the sheet and to support the electronics during launch. These panels are supported by a lightweight superstructure comprised of a series of tensioned cables and two compressive columns. This design is shown to meet all structural requirements for deployed frequency, geometric accuracy in the deployed configuration, and stowed loads while minimizing weight stowed volume and complexity. Analysis results for deployment kinematics, deployed mode shapes, surface geometry errors due to thermal excursions, and reaction wheel disturbances are summarized.