The R&S ATS1800M from Rohde & Schwarz is an extension of the compact R&S ATS1800C, a CATR-based 5G NR mmWave test chamber for over-the-air (OTA) testing. The additional side chambers enables the system to become what is presented as the only single-system solution available that enables full 3GPP-specified conformance testing of a 5G NR mmWave device. This includes testing for radio resource management (RRM), including multiple angles of arrival (AoA).
Presenting an innovative technology for OTA testing, the test chamber has a gold-plated CATR reflector that creates a large quiet zone (QZ), or usable measurement area. Offering a high level of performance in a compact form factor, the R&S ATS1800C also supports methodologies such as thermal and out-of-band (OOB) testing, while also providing support for RRM testing with two AoAs. The R&S ATS1800M has four CATR reflectors, each with a 30 cm quiet zone, overlapping and form a combined quiet zone of 30 cm at their intersection. This surrounds the device under test (DUT) with a large QZ from every direction.
The solution allows the DUT to be examined under real-world operating conditions, when exposed to signals arriving simultaneously at different angles. The large QZ results in a significantly lower measurement uncertainty compared to legacy solutions. The DUT can also be tested with random antenna locations ("black box testing"), making it an ideal solution for service providers.
RRM testing leverages limited RF resources in an optimal fashion while helping avoid co-channel interference. The 3GPP specification for RRM testing defines five different pairs of angles, with relative angular differences of 30°, 60°, 90°, 120° and 150° between the base station signals. Able to create a solution to meet this requirement with only three additional reflectors, the R&S side chamber extension is both retrofittable and reversible for existing R&S ATS1800C units.