Physically Controlled CubeSat Antennas With an Adaptive Frequency Operation

Abstract

This letter advocates the use of mechanical actuation to alter the electrical length of components within antenna elements proposed for implementation onto a CubeSat platform. Such electrical length alteration reconfigures the antenna's frequency operation without affecting its polarization scheme. This concept is first demonstrated on a reconfigurable quadrifilar helix that reconfigures its frequency operation between 750 MHz and 1 GHz, while maintaining a circular polarization behavior. As a second demonstration, a Yagi-Uda antenna is reconfigured by changing the electrical length of its reflector, fed elements, and two directors. Such alteration results in a frequency reconfiguration between 1.2 and 1.5 GHz, while preserving the linear polarization behavior of the antenna array. For both antenna examples, the reconfiguration is implemented through the appropriate mechanical actuators that are integrated within the CubeSat's cavity. As a proof of concept, both structures are fabricated and integrated on the outside chassis of a 6U CubeSat (10 × 20 × 30 cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sup> ), where measured results greatly match the simulated data.