82 Keysight EXG and MXG X-Series Signal Generators User’s GuideOptimize PerformanceUsing Flatness CorrectionUsing Flatness CorrectionUser flatness correction allows the digital adjustment of RF output amplitude for up to 1601sequential linearly or arbitrarily spaced frequency points to compensate for external losses incables, switches, or other devices. Using an Keysight N1911A/12A, E4419A/B, or U2000 Seriespower meter/sensor to calibrate the measurement system, a table of power level corrections canautomatically be created for frequencies where power level variations or losses occur. Supportedconnection types to the power meter/sensor are Sockets LAN, VXI–11 LAN, USB, and GPIB via VXI–11 LAN using a LAN–GPIB gateway (e.g. E5810A Gateway or equivalent).If you do not have an Keysight N1911A/12A or E4419A/B power meter, or U2000A/01A/02A/04Apower sensor, or if your power meter does not have a LAN, GPIB, or USB interface, the correctionvalues can be manually entered into the signal generator.To allow different correction arrays for different test setups or different frequency ranges, you maysave individual user flatness correction tables to the signal generator’s memory catalog and recallthem on demand.Follow the steps in the next sections to create and apply user flatness correction to the signalgenerator’s RF output (see page 86).Afterward, follow the steps in “Recalling and Applying a User Flatness Correction Array” onpage 90 to recall a user flatness file from the memory catalog and apply it to the signal generator’sRF output.A power meter with GPIB requires using the Connection Type VXI–11softkey, as well as a LAN–GPIB gateway, to control a power meter. Refer tothe Keysight Connectivity Guide USB/LAN/GPIB Connectivity Guide(E2094–90009), Keysight X-Series FAQs “How do I connect to the LAN?”,and to the E5810A User’s Guide or equivalent, LAN/GPIB gateway device.