Agilent Technologies E4406A, User Manual

Page: 163 / 230

Chapter 5 163
Functional Testing
Phase Noise
Phase Noise
Test Limits
Test Description
The phase noise test verifies that phase noise is within acceptable
limits. In this test, the source is connected to the RF Input. With the
input attenuator set to 10 dB, the source output amplitude is adjusted
to a 7 dBm. Input attenuation and source level remain unchanged
throughout the test. The noise marker function is used to measure the
phase noise at various offsets from the center frequency.
NOTE
When phase noise is measured, the phase noise of the source and the
UUT are combined. Phase noise components only add, and therefore
the phase noise of the source is an important consideration. The limits
and measurement points for this test have been established for a source
with an absolute SSB Phase Noise of
≤
110 dBc at 10 kHz offset and
≤
120 dBc at 30 kHz offset. If you are using a source other than those
recommended in Table 5-1 on page 142 , ensure that it meets the
critical specifications listed. However, if your source does not meet these
specifications, you can complete the test by increasing the test limits.
Alternatively, the spectral purity of most sources can be improved by
connecting the source frequency reference to a house reference (usually
10 MHz).
Center
Frequency
(MHz)
Frequency
Offset
(kHz)
Limit
(dBc/Hz)
600 10
≤ −
85
600 30
≤ −
90
900 10
≤ −
80
900 30
≤ −
90
1900 10
≤ −
70
1900 30
≤ −
90