NIRFSA_ATTR_DIGITIZER_SAMPLE_CLOCK_TIMEBASE_RATE
Specific Attribute
| Data type |
Access | High Level Functions |
|---|---|---|
| ViReal64 | R/W | N/A |
Description
Specifies the frequency, in hertz, of the external clock used as the timebase source if NIRFSA_ATTR_DIGITIZER_SAMPLE_CLOCK_TIMEBASE_SOURCE is an external source.
If timebase rate is set to a value below 60 MHz, signals at frequencies just above the 20 MHz passband of the downconverter may be aliased back into the passband. This aliasing occurs because the IF frequency of the downconverter is at 15 MHz, and the upper end of the passband is at 25 MHz. At sampling rates below 60 MHz, the Nyquist frequency is close to the end of the passband and creates aliases that are not effectively filtered by the downconverter.