Demystifying Over-the-Air (OTA) Testing

Given the increasing integration of chipsets and antennas as well as usage of higher frequencies, the lines between testing chipsets, RF testing and antenna characterization have become blurred. In upcoming mm-wave architectures (involving signals with wavelengths in the general millimeter region), there will be no connector between RF components like chipsets, a power amplifier (PA) and the attached antennas. Therefore, the chipset cannot be tested without the antenna and vice versa.

Both analog and digital improvements are leading to the use of multiple radio frequency (RF) frontends, massive antenna arrays even in consumer grade hardware, and a combination of beamforming and multiple-input multiple-output (MIMO) technology known as massive MIMO, enhancing multi-user MIMO (MU-MIMO), and supporting high user capacities in the 5G New Radio (NR) standard.

Future technologies and standards will make over-the-air (OTA) testing mandatory. At the same time, integrated antennas are becoming more common with each development cycle such as for low-cost IoT devices and 5G mmWave devices. Since measurement requirements will change with OTA testing, engineers need a basic understanding of antennas and antenna measurements.

This white paper provides you with extensive knowledge on the following:

• Antennas in general, their parameters and different types, as well as antenna characterization and testing
• The importance and execution of OTA test setup calibration
• General concepts that are valid for any OTA test setup, e.g., in-chamber or lab-bench setups
• Calibration verification
• Array antenna calibration methodologies.

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