It took a bit longer than originally hoped, but today we release the LANforge RF Attenuator, version 1.0. This system has 3 ATS0760-95 attenuator modules, with 0 to 95.5dB attenuation programmable in 0.5dB steps. These modules support 0.7Ghz to 6Ghz frequency, so it handles all current WiFi frequencies. It can be tightly integrated with the LANforge WiFIRE testing tools, and can be used standalone as well.
Full source code, including Arduino shield PCB files are released under GPL and CC-BY-SA licenses.
We are still waiting for the semi-rigid SMA cables (and hoping they will give us a bit better isolation), but even with just the standard double-shielded cable we feel the results are acceptable. Here is a link to some test results using the LANforge WiFIRE test systems (based on ath9k NICs) and the attenuator.
If you have any questions, please send email to: firstname.lastname@example.org