Here is our mixer circuit block diagram.
The IF noise floor measurement results at 21.4 MHz from the evaluation board with the circuit above as below.
- Low band mixer LTC5510 always has higher noise floor than high band mixer LTC5548;
- From datasheets, LTC5548 also has lower NF specs than LTC5510’s by about 2 to 3 dB.
So the question, I'm wondering why is the noise floor of LTC5548 is lower than LTC5510, in the same test setup, measured in the same time and environment? Is it because of the part's nature itself or there are some other factors at play?