304                                                                                                                     Keysight N9927-90001 User’s Guide
Over–the–Air Measurements (OTA) – LTE FDD Option 370 and 5GTF Option 377 (CPU2 
Only)
How to Set Up Over–the–Air (OTA) Mode Settings
Optional: Using RTSA to verify the signal quality (Requires Option 350 
and Preamp Option 235)
—Press Mode > RTSA
—Then Density Spectrum (Default)
—Press Freq/Dist
 > Center (Default) > 751 MHz
(For this example, Center = 751 MHz.) 
—Press Scale/Amptd
 
—Then Preamp [ON]
—Then Ref Level (Default). Then use the   arrows, the rotary knob, 
or numeric keypad to position the trace for optimum viewing on the 
FieldFox display. Refer to Figure 12-12 on page 304.
You should see a ~20 dB or greater LTE FDD signal–to–noise level. If not 
refer to “Troubleshooting” on page 326. 
Figure 12-12  Using RTSA to verify LTE FDD 751 MHz signal quality–20 dB Signal to Noise 
Displayed (Requires Option 350 and Preamp Option 235)