140 Keysig ht N9923-90001 User’s GuideFrequency Offset Using Power Sensor (FOPS) – Option 208FOPS Settings— Gain Not available until source data is stored into memory. Displays theOutput power / Source power (memory trace).— Rx Power Displays the raw received power at the USB power sensor.Sweep Type and FrequencySet the source and receiver frequencies for the FOPS measurements. Thereceiver is a Keysight U-Series Power Sensor. These are broadbandmeasurement devices, which means that they measure power over a very widefrequency range. Tables of frequency and power correction factors are storedwithin the power sensors. The receiver (R x) frequencies are used ONLY to applythe appropriate correction factors to th e power levels measured with the powersensor.How to set Sweep Type and Frequency— Press Freq/Dist— Then Sweep Type— Then choose from the following:— CW Used to make standard (non-offset) power meter measurements at asingle frequency. Learn more in “USB Power Meter Settings” on page 128.— Swept Used to make swept FOPS measurements.—— Then enter source (Src) frequencies as either Center and Spanor Start and Stop. Both methods set the FieldFox internalsource sweep range out the Port 1 RF Output connector.——The frequency limits are determined by the limits of both theFieldFox and the power sensor.——The LOW frequency is limited by the higher of either theFieldFox or the power sensor minimum frequencies.——The HIGH frequency is limited by the lower of either theFieldFox or the power sensor maximum frequencies.——Then More.——Then Freq Display. This determines how the receiverfrequencies below the graticules are displayed. Choose fromthe following:It is YOUR responsibility to ensure that ONLY the signal of interest ispresent at the power sensor. All other signals MUST be filteredappropriately.To make FOPS measurements at a single frequency, choose Swept, thenenter a Src Center frequency, then Span = 0 Hz.
