[maestroia]

The "6 GHz" band is an unlicensed frequency for very-low power (VLP) devices in the US.

Specific bands are: "U–NII–5 (5.925–6.425 MHz) and U–NII–7 (6.525–6.875 MHz)".

VLP is defined as those devices which "operate at up to −5 dBm/MHz power spectral density (PSD) and 14 dBm EIRP".

https://www.federalregister.gov/documents/2024/01/08/2023-28....

[mNovak]

14dBm EIRP is extremely low power for a radar however. Off the bat the author is using 1W (30dBm) PA, and you could readily get another 20dB from a moderate sized antenna (e.g. repurpose a scrap DirecTV dish).

Unless you're next to a base, it's the FCC that will come knocking long before the military.

[gambiting]

In fact you can get WiFi routers that use 6Ghz as the third band after 2.4Ghz and 5Ghz.