A self-deploying and self-stabilizing helical antenna for small satellites

Abstract

Space antennas with a helical geometry are an advantageous choice for many applications, for instance if the transmission of electromagnetic waves with a circular polarization is intended, or if signals from terrestrial objects shall be received with a high angular resolution. In all these cases the desired electromagnetic properties of a helical geometry can be combined with the mechanical advantage that the antenna acts as a compression spring, provided that its core structure has the necessary high spring stiffness but can nevertheless easily be compressed. Such an antenna has been developed by DLR Institutes in Bremen and Braunschweig together with some industrial partners for a small satellite named AISat which shall be able to pursue the position of individual ships in critical sea areas in order to improve the security of seafare trade. The development was very challenging since the antenna must expand from a stowed stack length of only 10 centimeters to a total length of 4 meters. Only a special carbonfiber core under the conductive coating and a system of stabilizing cords led to a satisfying solution. Both the self-deployment and the self-stabilization function of this innovative antenna concept have been successfully tested and verified under zero-gconditions in the course of a parabolic flight campaign. It could be convincingly demonstrated that the helical antenna can really achieve its desired contour in weightlessness within some seconds and maintain the required stability. Beyond the current application for the AISat satellite it is therefore a quite promising concept for future satellites.

Deployable Bistable Composite Helical Antennas for Small Satellite Applications

“…There are many stowage and deployment methods being investigated such as scrunch-up, roll-up, origami-folded, and actively controlled deployment mechanisms. AISat featured a 57 cm diameter, 4 m long helical antenna that deployed like a spring and was designed to receive AIS signals at 162 MHz [3,4]. Inherently small helical antennas (i.e.…”

A Beam Scanning Method based on the Helical Antenna for Space-based AIS

“…A helix antenna has strong directionality, can achieve higher gain and offer a steep gain slope in its antenna pattern, which reduces the footprint size and improves the power diversity in the received signals, is thought to be preferable to micro-strip patch antenna. A series of helix antennas had been constructed and verified by DLR for their future small AIS satellite "AISat" (Block et al, 2013). 3.1.…”

“…The German Aerospace Centre (DLR) designed a self-deploying and self-stabilising helical antenna of excellent directionality for a small AIS satellite to detect AIS messages with high 53 A B E A M S CA N N I N G A N T E N N A FO R S PAC E -B A S E D A I S NO. 1 gain and narrow footprint (Block et al, 2013). However, these two literatures mainly focus on the feasibility, electronic and structure design of the antenna and the performance of space-based AIS under these two antennae have not yet been systematically studied and verified.…”

On small satellites for oceanography: A survey

“…Launched in 2014, it is currently operational. In particular, the Institute of Space Systems is responsible for adapting the Clavis bus (an adaptation of the CubeSat platform by DLR) to this mission, while the Institute of Composite Structures and Adaptive Systems developed the helical antenna for the AIS payload[60]. Two companies (The Schütze Company and Joachims) and the Bremen University of Applied Sciences were also partners in the project.…”