ISBN 9783843942867

978-3-8439-4286-7, Reihe Raumfahrt

Maximilian A. Böttcher
Design of an active direct radiating array antenna for regional coverage in the Ka-band

244 Seiten, Dissertation Universität Stuttgart (2019), Softcover, A5

Zusammenfassung / Abstract

The focus of this dissertation lies in the design of an active antenna system for different broadband communication payloads for regional coverages in the Ka frequency band, that meets typical requirements of the satellite communication operators for adaptable concepts for the specific mission needs, rather than requiring specially tailored designs for every mission. This work focuses on a modular design for a direct radiating phased-array antenna, working in the 17.3-21.2 GHz frequency range for a GEO telecommunication payload of 500 MHz bandwidth, and featuring a one-amplifier-per-radiating-element concept. In order to optimize the overall size of the resulting antenna as well as the coverage area, different configurations of the radiating elements within the array and sub-array structures are investigated. This comprises nine combinations of different, standardized sub-arrays, each having a varying number of feed elements and different apertures of the horn feed elements.

The commercial software Pos of Ticra is used to optimize the excitation coefficients for a given regional coverage, and a link budget and data throughput analysis is performed to assess the designs’ performances, including the analysis of graceful degradation at end of life. As all designs use a large number of low-power GaN solid state power amplifiers, a special focus lies in the thermal design of such an array antenna,taking into account the selected back-off required for different waveforms and link budget requirements, and therefore the power dissipation of each solid state power amplifier. The commercial software Esatan-TMS of ITP Engines UK is used to create and analyze the thermal behavior of the active array antenna in the space environment and shows the effectiveness of a projected thermal control system.