TLDR; USB3.0 high speed signals when not properly shielded can cause RF interference with RF devices operating under 5Ghz due to the broadband nature of the signal.<p>@Mods, could be titled with [2012]
I have one USB3 128GB flash drive—manufactured right on the cusp of single-package 128GB NAND becoming available—where whenever I plug it into any device, it slow's that device's wi-fi to a crawl, and multiplies tenfold the jitter for any connected Bluetooth input peripherals. None of my other USB3 devices do it. I always figured it was a grounding problem or something.
I have had this annoying problem and had no idea what was going on until I stumbled upon forums somewhere after many Google searches. My Anker USB 3.0 hub would cause my bluetooth keyboard/mouse receivers to become unresponsive at random times (in retrospect at times when the hub was placed close to the Macbook Pro). I placed the hub at some distance from the MBP and voila the issue went away!
The graphs show an interesting quirk of RFI. In figure 2-1, the theoretical USB 3.0 emission spectrum has a zero at 5.0 GHz (equal to its signaling rate). In figure 2-2 the measurement has a significant narrowband spike at 5.0 GHz. Never believe zeros in spectra, there's usually something lurking under them. 2nd harmonic distortion probably causes it here.
Good timing - just last night I had my speakers plugged into the NUC make weird noises every time I scrolled using a USB mouse receiver plugged into a USB 3 port. I knew it was interference but couldn't have made the USB 3 connection without reading this.
I'll have to read through it, but I sometimes shut my wireless mouse and put it in its cradle when downloading a large file over my WiFi-tethered mobile phone, place the phone in a 45-degree angle instead of flat on my desk. No scientific reason, just guessing it puts it more in direct line with the WiFi antenna in my notebook and the tower.<p>It is my sole internet connection here in SE Asia, and this seems to help, but maybe I am wish-biased!
I also heard about this problem with Seagate 2.5" USB 3.0 external drives. Their cable included was not good shielded and it was causing problems with WiFi. Once the cable was exchanged with a good shielded one the problems are gone.
This is what all that tedious EMI testing and certification is supposed to prevent. Although I think it's much laxer for "conducted" emissions ..
I found out about this issue while purchasing an AC spec router last year:<p><a href="https://community.netgear.com/t5/Nighthawk-WiFi-Routers/Netgear-R7000-Vs-Asus-RT-AC68U/td-p/442063/page/7" rel="nofollow">https://community.netgear.com/t5/Nighthawk-WiFi-Routers/Netg...</a><p>The Asus RT-AC68U did not have proper shielding on their USB 3.0 hub (at least in their launch hardware revision) which lead to interference.
...does this explain why my bluetooth mouse or trackpad becomes unresponsive on my 2012 MacBook Air?<p>I haven't noticed a correlation with USB disk access and the mouse going limp, but now i'll be looking out for it.
This is almost a daily annoyance for me. I have a WD Passport Ultra HDD at work, and any time I plug it into the USB3.0 ports on my Dell E6430, my mouse (Microsoft Wireless Mouse 4000) gets laggy.
I remember listening to FM radio with either my smartphone or a nokia candybar, when I was in the bus or tram, the radio "cut" for 2 or 10s or even longer.<p>I think I remember it happened on both devices.
Found this out the hard way when I bought a little USB 3.0 hub off Amazon. You can plug it in and watch ping lose its lunch, then unplug it and the wifi returns to normal. (On a 2015 MBP).
Found out about this the hard way. I was confused why my Wi-Fi was slow. Disconnected USB3.0 external drive and bam, fast network again. Now I just have this drive as far away from the computer as possible, works fine.