Keysight Technologies NFA X-Series, Getting Started And Troubleshooting Manual

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Keysight NFA X-Series Getting Started and Troubleshooting Guide 29
Quick Start
Using the U7227-Series USB Preamplifiers in Noise Figure Measurements
Figure 1-7 Supported DUT Characteristics and Recommended Test System
Configuration for Frequency Ranges above 3.6 GHz
Figure 1-6 and Figure 1-7 provide a rough guide for frequency ranges up to
26.5 GHz. For the frequency ranges above, the U7227F USB Preamplifier used
together with the X-Series can support up to 50 GHz. The calculation method
for frequency ranges above 26.5 GHz is similar to the “3.6 GHz to 26.5 GHz”
frequency range. The supported DUT gain will decrease because of the
increase of the noise figure and gain for both the USB preamplifier and the
internal preamplifier. Refer to Table 1-1 and Table 1-2 .
For frequency ranges above 3.6 GHz, if no preamplifier is used in the signal
analyzer, the major noise power concern will be the noise power before the
mixer. In this case, the input noise outside the preselector bandwidth (less
than 80 MHz) will be filtered. This may affect the supported DUT
characteristics.