Dual polarised dual frequency axial array with iso flux pattern for low orbit space applications

Low orbit satellites often require a global earth coverage with iso flux shape to optimize the achievable gain but under the constrain of low mass and volume for the antenna solution. In this paper an innovative antenna configuration suitable for ARGOS satellite applications is reported. The antenna has been developed, manufactured and tested. Several antenna solutions ranging from different helix type antenna implementations to planar and 3D array constellations have been investigated and trade-off in an initial study phase. The final antenna structure selected for further investigation, elegant bread boarding and test is based on an axial dual element array configuration providing the desired iso-flux shaped pattern with minimum mass and overall size. The antenna is shown in Figure 1 during testing in the SATIMO SG-64 multiprobe spherical near field range. The antenna operates in right hand circular polarization at two narrow band frequencies for Tx/Rx operation centred around 402MHz and 466MHz and has an iso-flux type radiation pattern in the angular range from 0° to 63°. Although not required for the specific application the antenna configuration can support dual polarization with separate inputs. The electrical performance, thermal and mechanical issues and the minimization of the overall mass and envelope have been the design drivers in the study. This paper describes the pertinent phases of the study: Considerations on the antenna design trade-off activity, selection of the candidate antenna technology, manufacturing, tuning and final testing including considerations on the associated measurement uncertainty.