Summary
International Symposium on Antennas and Propagation
2010
Session Number:3TF2
Session:
Number:3TF2-3
A multi-purpose, multi-frequency Shuttlecock Antenna for CubeSats
R. Lehmensiek,
pp.-
Publication Date:2010/11/23
Online ISSN:2188-5079
Summary:
CubeSats [1] may use radio communication systems in various frequency bands [2]. Due to the space constraints on a CubeSat and because the system’s power availability needs to be maximised by means of maximising the solar panel surface area, the number of possible payload devices and antennas on the satellite, and the size thereof, is limited. Thus there is merit in using a multi-frequency single-port antenna which can transmit and receive on several frequencies using a single antenna structure. Furthermore, if this antenna structure also forms part of a passive aerodynamic attitude stabilisation system, it provides for a very attractive solution. CubeSats typically have little or no attitude control because the traditional attitude stabilisation systems used on larger satellites, i.e. sensors and actuators, are impractical due to their size, weight and power budget requirements. However, for low earth orbiting satellites at altitudes below 500 km it is feasible to use aerodynamic drag torques together with a damping mechanism for rough attitude stabilisation. In [3] thin metallic strips or feathers (due to the resemblance to a badminton shuttlecock) that deploy after launch from the rear of the satellite were used. These feathers stabilise the satellite in pitch and yaw due to the passive aerodynamic drag torques. The damping was done using an active magnetic torque control system. In this paper a multi-purpose four-feathered satellite antenna (similar to that in [3]) that is used both for passive attitude stabilisation and as a multi-frequency antenna is investigated for a 3U CubeSat. The four feathers made from thin metallic strips are connected to a passive impedance matching network at the rear of the satellite. The matching network combines the four feathers and impedance matches to a single port 50 ohm coaxial connector. The antenna was designed to radiate at the amateur satellite communication frequencies: 435 ? 438 MHz (UHF) and 1260 ? 1270 MHz (L-band). Bandstop filters are cut into the metal strips to suppress currents along the length of the wire to simulate shorter or longer wire lengths at different frequencies, thus creating a multifrequency antenna. Full-wave electromagnetic analyses of the complete antenna structure on a 3U CubeSat are presented.