Equivalent source and pattern reconstruction from oversampled measurements in highly-reflective environments

Measurement errors due to echoes are a major challenge for accurate antenna pattern measurements. In particular in highly-reflective measurement environments, the echo contribution can easily have more influence on the measurement signal than the desired line-of-sight contribution between the antenna under test and the measurement probe. A large number of redundant measurement samples at different locations and for different frequencies is used together with appropriate post-processing techniques to mitigate the echo influences on the measurements. The frequency diversity is used for time gating. A virtual array, less sensitive to the undesired echo fields, is formed using probe diversity. In this work, the common time gating technique is enhanced and the impact of different probe configurations for creating a virtual array is investigated. The utilised time gating method extends the measured frequency domain signal to mitigate the Gibbs phenomenon. Processing measurements in a quasi-metallic room, the signal contributions at the edges of the measured bandwidth do not suffer from distortions with the enhanced time gating method. Combining up to 115 probes to form a virtual array, it is found that the results improve with an increasing number of probes as long as the probes are distant enough from the walls.