Pattern Correction From Nonideal Compact Antenna Test Range Measurement

The nonideal plane wave in the quiet zone (QZ) of the compact antenna test range (CATR) can cause measurement errors for some antennas under test (AUTs). This letter presents the reference antenna (RA) method to correct the AUT pattern measured in the non-ideal CATR. By equating CATR as a probe antenna, the output voltage can be expressed as the coupling between CATR and AUT in the mode domain. To implement the correction, the RA of the pattern pre-known needs to be measured in the same CATR. The output voltages of the AUT and RA contain the same CATR modes; hence, the AUT can be corrected by de-coupling the CATR modes in the mode domain. To ensure the correction accuracy, the selection criteria for RA and the maximum mode order required for far-field (FF) correction are also discussed. Furthermore, since the correction method is independent of the size of QZ, it also can be utilized for the correction of AUT larger than the QZ, providing a way to expand QZ. Several full-wave simulations demonstrate the method.