When working on radio related things in a lab, there are usually shielded boxes with antenna connectors and attenuators, so it’s easy to simulate bad RF conditions. That’s quite useful when testing how devices behave under such conditions. Recently, I wanted to see how a router with an LTE modem behaves when RF is bad from home, so I had to come up with a different approach: Anti-static bags.
Apart from being anti-static, those bags, that are used to ship electronic components, also attenuate RF signals pretty well. In the picture above, a single bag over the LTE transmit antenna of the device reduced uplink throughput from 20 Mbit/s to 2 Mbit/s instantaneously. A nice bonus: Putting the anti-static bag over the other antenna had no effect as the LTE uplink only uses one TX chain which is obviously fixed to one antenna on this device. And just in case the attenuation of one bag is not enough: Take two or three.