Over-The-Air Measurements Under Extreme Temperature Conditions

5G communications have supported the deployment of millimeter-wave antenna array beam-steering technologies at an unprecedented commercial scale. As per 3GPP and CTIA test specifications, 5G millimeter-wave capable mobile phones must undergo a large number of tests in order to guarantee an adequate performance for preserving the integrity of the mobile network. The defined measurement methodology relies on farfield Over-The-Air (OTA) assessments in Compact Antenna Test Ranges (CATR). As temperature influences the active electronics in the wireless devices and hence the beam-forming characteristics, OTA measurements are also required in extreme conditions ranging from -10 to +55◦C. This paper presents an innovative realization of a CATR with an embedded thermal chamber, meeting all conformance / compliance testing requirements. Inventive steps which were taken are explained, showing how the complex engineering problem to design a chamber and a system compatible with all mandatory criteria was solved. Specific characteristics of the combined OTA-thermal solution are demonstrated through thermal and RF measurements.