Before 5G, most wireless device tests were conducted using the wire method. This includes testing modem chipsets, radio frequency (RF) parameter testing, and complete equipment function and performance verification. The wireless (OTA) test method is mainly used for antenna performance test and equipment multiple input multiple output (MIMO) performance measurement. 5G millimeter wave equipment represents a disruptive shift in the wireless industry because Ota is the only feasible test method in all radio test cases.

       At mmwave frequency, higher path loss and shorter wavelength require controllable directional antenna (gain) - usually phased array antenna. In addition to the traditional LTE and frequency range1 (FR1) monopole antennas, many 5G devices also need multiple groups of mmwave antennas. Since the mmwave antenna must be directly connected to the RF front end (RFFE) amplifier, the equipment cannot be accessed and tested at a lower frequency, and the radiation test method is required.

      The traditional conducted RF test method uses high-performance coaxial cable between the measurement solution and the equipment under test (DUT). The OTA replaces the cable with an air link through which the DUT communicates directly with the antenna as part of the test solution. In order to ensure a good RF environment (i.e. test transmission lines and eliminate external interference), OTA connections are best managed inside the darkroom.

Typical scheme:

Related products: