The HackRF One from Great Scott Gadgets is a Software Defined Radio peripheral capable of transmission or reception of radio signals from 1 MHz to 6 GHz.
It can be used as RF receptor, spectrum alayzer, etc.
On Linux, you need to install the following packages:
In order to use the HackRF as a spectrum analyzer, the sweep mode can be used. An open source project provides an interface to use it: