[gruez]

> 5GHz actually has worse penetration and stronger attenuation over distance than 2.4GHz. Succesfully blocking 5GHz does not imply the same for 2.4GHz.

In this case it could be the opposite: faraday cages only work for blocking wavelengths that are longer than the wavelength that it's designed for (presumably 2.4ghz). Therefore it could be blocking 2.4ghz but letting 5ghz waves through because it's too small to contain.

[dhdc]

As long as the hole size in the faraday cage is much smaller than the wavelength, it will work. The front mesh of a microwave typically has openings on the order of millimeters, which is still good enough for 5GHz.