Electronically steered array antennas are becoming key components of modern satellite communication systems. To ensure reliable operation in low Earth orbit, medium Earth orbit and geostationary orbit, it is essential to accurately characterize their radiation pattern properties. However, traditional far-field testing often requires an anechoic chamber that is too large for Ku- or Ka-band antennas, especially when the antenna under test has an aperture of half a meter or more. Compact range test systems are still large for such antennas and require time-consuming dual-axis positioning to map radiation patterns.

In a recent joint test, R&S and Greenerwave achieved a major breakthrough in electronically steered array antenna testing. They obtained highly accurate radiation pattern characterization through near-field measurements and significantly reduced test time. Greenerwave’s innovative satellite communication user terminal is based on reconfigurable intelligent surface technology, enabling the company to design electronically controlled antennas that deliver high-performance connectivity while significantly reducing power consumption and dependence on semiconductors compared with traditional solutions.

In this joint test, test and measurement expert R&S provided the R&S TS8991 over-the-air and antenna test system equipped with a conical cut positioning device, as well as the R&S ZNA vector network analyzer. The two parties jointly evaluated Greenerwave’s passive single-aperture electronically steered array antenna using RIS beamforming technology. The antenna under test features a 50 × 50 cm aperture and is designed for low power consumption and easy integration.

The test used 1-degree steps to cover the extended upper hemisphere within a 120-degree polar angle range. With the system’s hardware trigger function, data acquisition at ten Ku-band frequency points was completed, significantly shortening the measurement time. The data was processed using the FIAFTA near-field to far-field transformation algorithm in the R&S AMS32 antenna measurement software.

Comparison with the original simulation based on a digital twin model and Greenerwave’s compact range test results showed that the maximum difference in peak gain/directivity was no more than 1 dB, with a typical value of 0.3 dB, fully verifying the accuracy of the near-field solution. The data export function allows users to perform further analysis in tools such as CST Microwave Studio or MATLAB.

This test demonstrates that even for large satellite communication antennas, a near-field test solution built with the R&S TS8991 antenna test system can achieve fast and accurate characterization, providing a practical alternative to large far-field anechoic chambers or compact range systems. This configuration is also suitable for other satellite communication manufacturers that need to test broadband, IoT or backhaul antennas, meeting their requirements for flexible beam control and high data rate applications. The system is easier to integrate into R&D laboratory environments, effectively shortening test cycles and reducing overall development costs.