The Aeroflex RDL DCR-2500A Downconverter has the lowest noise available and the levels are low enough, when combined with the NTS-1000B, to measure these extremely low levels.
The DCR-2500A is a unique downconverter in that the LOs inside have extremely low phase noise. There are three overlapping bands in the DCR-2500A that provide continuous frequency coverage between 1 GHz and 3.26 GHz. The output frequency range is bandpass filter limited to between 60 and 700 MHz.
This unit requires only a 0 dBm input level. The DCR-2500A has the gain inside so that an external low-noise amplifier is not required. Conversion gain is a nominal +3 dB and the DCR-2500A output is sufficient to drive the
NTS-1000B Phase Noise Analyzer.