Clocking

There are three modes of clocking to consider to acheived desired IQ rates on NI RF signal generators.

Divide-Down Clocking

Divide-down clocking divides an RF signal generator timebase to derive a unique frequency.

The divide-down clocking mechanism is preferred when possible because it offers the lowest jitter of the sample clock. However, IQ rates will be coerced to what rates the hardware can achieve. Read the value of the IQ rate back after setting it to see what the actual IQ rate is when using divide-down clocking.

High-Resolution Clocking

High-resolution clocking enables the most precise frequency resolution. This clocking mode is useful for applications that require a precise clock frequency, which is not possible using the divide-down clocking scheme.

High-resolution clocking is the preferred clocking mode to acheive precise IQ rates. However, high-resolution clocking has more jitter than divide-down clocking. Jitter produces increased IQ signal phase noise. Use divide-down clocking for the best possible phase-noise performance.

External Clocking

External clocking allows you to connect an external clock to the NI RF signal generator. This external clock can then be used as the Sample clock for the device.