The signals from the device under test (DUT) are picked up by an octoScope High Gain MIMO Antenna Array shown on the right in the photo below. This consists of 4 log-periodic antenna elements mounted on a plastic rail. These antennas are optimized for 2-6 GHz operation and offer 10 dB of gain in this band.
Only the center two antennas are used for throughput vs. attenuation testing with the octoScope Pal set to 2x2 mode. All four antennas are used when testing maximum wireless throughput with the Pal set to 4x4 mode.
ASUS RT-AC88U router inside Box-38 RF chamber
The antennas are equally spaced with the midline of the turntable bisecting the space between the center two antennas. And yes, the bamboo cable rod is still in service! The antennas have a new mounting system that is much easier to adjust.
Box-38 antenna detail
Box 18 Detail
octoScope's Box-18 is a lot smaller inside. So to maximize room for product under test, the chamber is equipped with simple unity-gain dual-band dipole antennas. Even though signal levels are lower than with octoScope's high gain antennas, the antennas are so close to the product under test that there is still plenty of signal. Each antenna is on a carrier that can be easily slid on its mounting rail and locked down using a thumb screw.
eero inside Box-18 RF chamber
We have long used Ixia's IxChariot as our throughput traffic generation and measurement tool. I'm thankful that Ixia has provided IxChariot for over 15 years at no charge. But it's now time to make a change for at least some of our test processes. The V10 process uses the open source iperf3 tool. The main reason for the change is better correlation with other octoScope users, who prefer iperf3's free price tag.
That concludes the tour of the Revision 10 testbed. How We Test Wireless Products - Revison 10 (coming soon) describes how we use it.