Measurement of Low Frequency Antennas in Indoor Reflective Environments with the Synthetic Probe Array Technique

Performance verification of low gain antennas on small space platforms are challenging at frequencies below 400MHz, also owing to limitations in the anechoic environment. Spherical near-field measurement techniques are often applied in such cases, enabling different echo-reduction schemes to compensate for the non-ideal test environment. Uncertainties due to chamber reflections are also reduced with a directive probe but electrically larger probes are impractical at very low frequencies because of the resulting physical dimensions. A virtual probe, synthesized from an array of smaller probes, with limited wall illumination has been developed to reduce this error. The concept has been developed for measurements in the ESA/ESTEC HERTZ testing facility of the HERA-JUVENTAS mission with a 50–70 MHz dipole antenna mounted on a CubeSat. In this paper, we present the concept, feasibility, and verification by measurements on a 10:1 scaled representation of the CubeSat scenario and the HERTZ facility.