Study Of OTA Test For 5G Millimeter Wave Active Antenna

Since the 1980 s,mobile communication systems are constantly evolving as the demand for communications has grown.Nowadays,5G are already commercially available and widespread in China.The mobile communications standardization organization 3GPP has defined two frequency ranges for 5G: the FR1 band and the FR2 band,also known as the Sub-6G band and the millimeter-wave band.The measurement method for the Sub-6G band is relatively similar to the 4G test method.In the millimeter-wave band,the 5G active antenna integrates the RF circuitry and the millimeter-wave antenna together.This integrated design brings great challenge to antenna testing and RF testing,making the traditional conducted test method no longer applicable and therefore requiring an OTA test method.Based on antenna measurement and 5G RF test theory,this thesis focuses on the research and design of millimeter-wave OTA testing.the main works are as follows:1.Research on millimeter-wave CATR test systems.The millimeter-wave OTA test needs to provide a plane-wave test environment.Based on the small size and relatively low cost of the CATR,this thesis has designed a millimeter-wave CATR test System.The structural parameters of the antennas are calculated through the theoretical formulas of four-ridged horn antenna and single-offset paraboloidal antenna and optimized after simulation.In this thesis,the design principle of a four-ridged horn antenna is first studied and analyzed,and a dualpolarized,wide-band feed antenna is designed to meet the requirements.Then a further design of a rolled-edge reflector antenna with a bias-fed CATR system was designed.The final simulation results show that the-10 d B impedance bandwidth of the feed antenna covers the band from 23.5 GHz to 39.8 GHz,and the gain is maintained above 9 d Bi in all operating bands.The CATR test system forms a 140 mm * 140 mm quiet zone,whose amplitude fluctuation is less than 1 d B and phase fluctuation less than 10°.2.A study on the 5G millimeter-wave active antenna OTA test system.Based on 5G Sub-6G integrated test instrument and millimeter-wave transceiver,the designed system enables low-cost transmitter RF testing of 5G millimeter-wave active antennas with a simple upgrade.According to the OTA system design plan,the OTA test simulation model is built in the RF system architecture simulation software,as well as the Sub-6G active antenna test platform in laboratory.The OTA test system shows that the simulated results and measured results are basically consistent,and the conduction test results and OTA test results basically match,with power measurement error within 1 d B and non-linear measurement error within an acceptable range of 2?3 d B,which means that the designed system is suitable for OTA testing of 5G active antennas.