As the world rolls out 5G networks, the evolution of the 5G NR standard continues. The upcoming Release 17 from the 3GPP partnership will extend frequency support for 5G NR millimeter-wave (mmWave) bands into the unlicensed spectrum up to 71 GHz, a frequency band traditionally used by non-cellular standards such as IEEE 802.11ad and 11ay. For evaluating RF transceiver chipsets, that means new testing challenges — something that both test-and-measurement solutions provider Rohde & Schwarz and chip and integrated modular supplier Sivers Semiconductors had in mind when they collaborated to test 5G RF transceivers.
The bandwidth extension, set to be implemented by mid-2022, requires both an adaptation of the physical layer and the support of wider signal bandwidths. This poses challenges for RF transceiver manufacturers targeting cellular applications, and it also opens opportunities for those designing and manufacturing transceiver chipsets for non-cellular IEEE standards operating in these mmWave bands.
For the joint testing efforts, Sivers Semiconductors provided an evaluation kit as device under test (DUT), powered by the Radio Frequency Integrated Circuit (RFIC) TRXBF01 and the RF antenna module BFM06010. The RFIC supports IEEE 802.11ad/ay modulations up to 64QAM over the full frequency range from 57 to 71 GHz. For its part, Rohde & Schwarz provided the R&S SMW200A vector signal generator, which possesses a new frequency option that supports frequencies up to 67-72 GHz in overrange mode; and the R&S FSW85 signal and spectrum analyzer, which offers integrated signal analysis bandwidth of up to 8.3 GHz and supports RF frequencies up to 90 GHz. The R&S ATS1800C compact antenna test range (CATR) based 5G NR mmWave test chamber completed the over-the-air (OTA) testing setup.
For validating transmitter performance, the vector signal generator provides a differential analog IQ baseband signal to the DUT, which in turn performs IQ modulation of the signal and up-conversion to the desired RF frequency. The generated signal is compliant to Release 17 and uses a 960 kHz subcarrier spacing — one of two new spacings required by the bandwidth extension. The DUT next focuses its transmitter beam toward the CATR reflector. The signal is bundled to the feed antenna and provided to the input of R&S FSW85 for signal analysis.
To test DUT receiver performance, the vector signal generator provides a 64 GHz signal while connected to the test chamber’s feed antenna, which directs it toward the CATR reflector. This creates far-field conditions within a high-quality, 30 cm-diameter quiet zone (QZ). Repeatable RF measurements of the DUT within the QZ are enabled by the integrated positioner. Finally, the Sivers Semiconductors chipset converts the received signal into baseband that gets captured by an R&S RTP oscilloscope and processed for individual signal analysis.
Andreas Pauly, Executive Vice President Test & Measurement at Rohde & Schwarz, remarked that the collaboration demonstrated the company’s commitment to partners and customers. “Through this, we enable them to develop cutting-edge technology that will make advanced use cases of 5G for consumers and enterprises a reality.”
A video presentation about the testing collaboration is available to registered users of the Rohde & Schwarz site.