End-to-End Testing of Low Frequency Antennas in Highly Reflective Environments

End-to-end measurements of the radiation performance of low gain antennas where the phase is not accessible, like on small space platforms, are challenging at low frequencies like 20-100 MHz because of the poor reflectivity of the measurement environments. To compensate for the non-ideal test scenarios, echo reduction schemes like modal filtering and time gating can only be applied to classic passive measurements, where the phase information is available. Moreover, such techniques are barely effective at such low frequencies because of reduced electrical size of the measurement environment. In this paper, a probe array working as plane wave generator is proposed to perform end-to-end characterization of low-frequency devices. The technique is based on a suitable optimization of complex coefficients of the probe array elements, generating a far field condition (i.e. approximate plane wave) over a finite testing volume called the quiet zone, while reducing the illumination of the chamber walls, and the hence the reflections.