Similar to 5G networks and devices supporting mmWave frequencies, antenna systems and RF transceiver modules for future mobile communications standards or automotive radar applications will share the same features that make their testing a challenge. Their wide frequency range, a greater number of antenna elements and the lack of conventional external RF connectors will demand testing over-the-air in a shielded environment. Wireless communications test expert Rohde & Schwarz and IHP GmbH (Innovations for High Performance Microelectronics) have transferred this test method successfully into sub-THz range by demonstrating the first full 2D/3D over-the-air measurements of a radar module at D-Band frequencies.
The test setup consists of the ATS1000 antenna test system, the ZNA43 vector network analyzer and the AMS32 antenna measurement software from Rohde & Schwarz. The ATS1000 antenna test system is a compact and mobile shielded chamber for OTA and antenna measurements, ideal for 5G mmWave applications. To cover the D-Band frequencies, extensions from Radiometer Physics GmbH, a Rohde & Schwarz company, are used in the setup, which allow direct frequency conversion at the probe in both transmit and receive directions. No mechanical modifications or additional RF cabling to the antenna test system is necessary. The setup can measure the amplitude and phase coherent response of a DUT radiating in the D-Band. Fully automated 3D-pattern measurements including post-processing can be performed in short time thanks to the AMS32 software options for nearfield to farfield transformation and the highly accurate precision positioner.