D-Band range from 110 GHz to 170 GHz can be used for 5G and 6G mobile communications as well as for future automotive radar applications
Antenna systems and RF transceiver modules of future mobile communications standards or automotive radar applications will share similar features of 5G and mmWave frequencies. 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, making tasks related to testing a challenge.
Now the test method for this problem has been successfully demonstrated through 2D/3D over-the-air measurements of a radar module at D-Band frequencies. The test setup consists of the R&S ATS1000 antenna test system, the R&S ZNA43 vector network analyzer and the R&S AMS32 antenna measurement software. The R&S ATS1000 antenna test system is a compact and mobile shielded chamber solution for OTA and antenna measurements, ideal for 5G mmWave applications. To cover the D-Band frequencies, several extensions have been used in the setup, which allows 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. Thanks to the R&S AMS32 software, fully automated 3D-pattern measurements including post-processing can be performed in a short time for nearfield to farfield transformation and highly accurate position.
The performance of the various DUTs has been characterised by spherical measurements, using two different setups. By increasing the angular theta step-size from 1 degree to 5 degrees, the total test times for a DUT could be reduced from 70 minutes to 12 minutes. By comparing the different DUT designs based on the obtained measurement data, the effect of the finite on-board reflector area on the radar sensor FoV (field-of-view) can be analysed.
The project is conducted by Rohde & Schwarz in collaboration with IHP GmbH (Innovations for High Performance Microelectronics)
“Sub-THz frequency systems are getting more and more attention in research and many fields of application. The OTA test system extended to D-Band, provides an excellent way to characterise radiation patterns of the complex antenna structures, realised in our D-Band radar chips, in a time-efficient and precise way. These measurements are valuable to understand the physics of the antenna structures and to further improve their performance. The very successful cooperation with an industrial partner leading in the field of wireless and mmWave communication shows the benefit of close interaction between research and application,” said Prof. Gerhard Kahmen, Managing Director of IHP.
Alexander Pabst, Vice President of Systems & Projects at Rohde & Schwarz says: “We are excited to work with IHP on advancing our industry-leading test solutions for over-the-air testing. These joint efforts will help researchers and key industry players to test and characterize antenna systems and transceiver modules for future automotive radar applications and wireless communication standard, that we eventually call 6G.”