The DSG821A from RIGOL Technologies is a Signal Generator with Frequency 9 kHz to 2.1 GHz, Resolution 0.01 Hz, Output Power Up to 20 dBm, Phase Noise Up to -112 dBc/Hz, SSB Phase Noise -112 to -99 dBc/Hz. Tags: RF Signal Source. More details for DSG821A can be seen below.