Robert Lehmensiek

Comparison of the communication time of a high gain versus a low gain monopole-like low profile antenna on a 3-unit CubeSat

This paper investigates the effect of the antenna pattern on the communication time between a ground station and a low earth orbit satellite with passive attitude control, i.e. the antenna is nadir pointing. Two low profile antennas that fit on a 3-unit CubeSat are considered, namely a high gain patch and a low gain monopole-like patch antenna. The communication system is for high speed S-band communication.

The design of an HF antenna on a 1U CubeSat

This paper presents the design, the deployment mechanism and the measurement of an HF antenna on a 1U CubeSat. An HF radio beacon on this CubeSat shall be used as a space-based signal source to contribute to the monitoring of the density and movement of the polar and high-latitude ionosphere making use of the interferometer antenna arrays at the South African Antarctic station, SANAE-IV.

The synthesis and optimizationof a diplexer for the multi-purpose, multi-frequency shuttlecock antenna

This paper describes the synthesis procedure and optimization algorithm developed to design a diplexer for the multi-purpose, multi-frequency Shuttlecock antenna. Starting from a low order circuit topology the synthesizer increases the order until the set of specifications are adhered to. The circuit element values are determined by a hybrid optimization algorithm that combines a global search algorithm and a downhill simplex method.