NI 5650/5651/5652 Power Level Adjustment

Fine amplitude adjustment is performed by the automatic leveling control (ALC) loop, and coarse attenuation is performed by the attenuators. The ALC is calibrated for amplitude and temperature variation and is used to control the upper 10 dB. When possible, NI-RFSG uses only the ALC to get the specified power. However, if more than 10 dB of attenuation is needed at the specified frequency¹, then the attenuators are used. For this reason, signal amplitude has best absolute and relative accuracy at the uppermost 10 dB, which is typically better than specified. Below the first 10 dB of power, the attenuators assert and error increases.

Note  Refer to the specifications document that shipped with your RF signal generator for guaranteed output power ranges.

¹Power range varies depending on frequency.