A millimetre wave semi-compact antenna test range

A new technique for the measurement of antenna far-field patterns at millimetre wave frequencies is described and is based on a hybrid between the Compact Range and the near-field to far-field transformation method. A pillbox antenna forming the near-field probe performs instantaneous integration of the field in one dimension. Near-field patterns of antennas are measured and processed and far-field predictions produced within one minute on a standard 386 microcomputer. The technique is particularly suited for testing antennas on a production line. It is shown that far-field predictions from amplitude-only data can be obtained, hence providing a very low cost and yet accurate indoor antenna measurement facility. Modal filtering for reducing systematic noise in measured far-field patterns is demonstrated