Reflection Suppression in cylindrical near-field measurements of electrically small antennas

Reflections in antenna test ranges can often constitute the largest single term within the error budget of a given facility. For some time, a technique named mathematical absorber reflection suppression (MARS) has been used to reduce range multi-path effects within spherical near-field and far-field antenna measurement systems. Whilst the technique presented herein is also a general purpose measurement and post-processing technique, uniquely, this technique is applicable to cylindrical near-field antenna test ranges. Here, the postprocessing involves the analysis of the cylindrical mode spectrum of the measured field data which is then combined with a filtering process to suppress spurious scattered signals. This paper provides an introduction to the measurement technique and a description of the novel near-field to far-field transform algorithm before presenting preliminary results of actual range measurements of a low gain antenna. These results illustrate the success of the technique which is found to yield improvements comparable to those attained with the corresponding spherical MARS technique.