Deployable Wideband UHF Antenna for Small Satellites
Researchers and Collaborators
In recent years there has been a renewed interest in small satellite platforms, such as CubeSats. These satellites can provide lower cost access to space and typically have shorter development cycles and higher risk tolerance, making them ideal for innovation. However, due to the strict space requirements on these satellites, deployable structures are often required for large components. With this renewed interest there is a need for higher performance antennas which tend to be large, making them a likely candidate for deployable structures.
Simples antenna types have previously been favored for small satellite applications such as monopole antennas. Though these simpler antenna types are easy to design and deploy, they are typically not an efficient solution. The broad objective of this research is to develop a design methodology for deployable composite antennas for small satellites. This involves identifying antenna types appropriate for space applications, developing associated structural concepts and packaging schemes, and establishing scaling principles between the electromagnetic, structural, and material constraints. An initial antenna classification based on their typical bandwidth and gain, coupled with structural properties is shown below. These tools are then applied to case studies to demonstrate a complete design cycle, taking a problem from requirements through detailed design to testing.
A representative case study is of a high performance antenna with a gain of at least 5 dB operating over a 300-600 MHz range that is circularly polarized. It also must fit in half of a 3U CubeSat volume and must meet the stiffness requirement of f0 > 1 Hz. One solution is a conical log spiral antenna constructed from a dual-matrix composite shell with a thin mesh conductor embedded at the mid-plane of the composite lay-up. The shell can be flattened and folded using silicone hinges integrated into the shell, as shown in the figure below.
A prototype fabricated using an Astroquartz/Epoxy shell with Astroquartz/Silicone hinges has been tested for electromagnetic and structural performance demonstrating that the design meets all requirements and that performance is not affected by the folding and unfolding of the structure. A deployment concept using a dual-matrix closed cross-section deployable boom has been developed, as shown below, and studied in simulation.
A second solution involves a helical or quadrifilar-helix antennas, and uses helical composite supports winding in the opposite sense of conductors to form a helical pantograph, as shown below. The structure is compacted axially much like a linear pantograph, and can be compacted in the transverse direction by simply pulling four or eight points inward.
- Sakovsky, M., Pellegrino, S. and Mallikarachchi, H.M.Y.C. (2016). Folding and deployment of closed cross-section dual-matrix composite booms. SciTech 2016, San Diego, AIAA-2016-0970.
- Sakovsky, M., Maqueda. I., Karl, C., Pellegrino, S., and Costantine, J. (2015). Dual-Matrix Composite Wideband Antenna Structures for CubeSats. AIAA Spacecraft Structures Conference, 5-9 January 2015, Kissimmee, FL, AIAA 2015-0944
- Olson, G., Pellegrino, S., Costantine, J., Banik, J. (2012) Structural Architectures for a Deployable Wideband UHF Antenna, 53rd AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics and Materials Conference, Honolulu, HI, April 2012.