Head-to-Head Coaxial Interconnect vs OTA Testing for 5G

Without question, the rise of 5G has changed the landscape of wireless testing. One of the biggest changes is the ability of test engineers to perform over-the-air (OTA) testing without connecting anything or having a special setup. This is something that was not historically possible with past generations of wireless devices, as a result of FCC regulation and spectrum licensing law. OTA testing has the potential to revolutionize wireless device testing and enable innovative testing of advanced antenna systems (AAS) and antenna array technology.

However, there are several critical disadvantages of OTA testing that limit its applicability to all 5G sub-6 GHz (5G FR1) and millimeter-wave (5G FR2) device testing. One such consideration is the variability of OTA testing, which appears to be many times that of traditional coaxial transmission line test methods. Equally, there are limitations to coaxial test methods addressing the test needs of the latest beamforming and multi-input multi-output (MIMO) antenna technology. It is becoming increasingly clear moving forward that successful testing of 5G wireless technology must include OTA and RF over coax testing to tackle the pre-existing and emerging challenges of 5G device performance and conformance testing. What is most important is to understand the advantages and disadvantages of both to determine where and when to use each test approach.