A Proposal of Near-Field Measurement System Using Software Defined Radio for 5G Antenna Pattern Measurement

Although 5G has been in operation for several years, the 28 GHz band has not been widely used in most countries. One reason is that the measurement environment required for development is expensive, creating a high barrier to entry. Near-field measurements are widely used to evaluate antenna patterns because they do not require a large anechoic chamber. However, it is expected that future mobile terminals and antenna systems will not have RF connectors and cannot be directly connected to a measurement instrument. Such devices require over-the-air (OTA) measurements, which are difficult to perform using conventional Vector Network Analyzers (VNA). In this study, we proposed a near-field measurement system using a software-defined radio (SDR) to perform OTA measurements at a lower cost and more conveniently than conventional methods. As a result, although some issues remain to be resolved, a way of realizing OTA antenna pattern measurement using an SDR has been confirmed.