Anritsu 682XXB - Manual (Page 82)

3-10
SINGLE SIDEBAND
PHASE NOISE TEST The following test can be used to verify that the signal generator
meets its single sideband phase noise specifications. For this test, a
second 682XXB/683XXB is required. This additional instrument acts
as a local oscillator (LO). The CW RF output of the 682XXB/683XXB
under test (DUT) is mixed with the CW RF output from the 682XXB/
683XXB LO which is offset by 1 MHz. Single sideband phase noise is
measured at offsets of 100 Hz, 1 kHz, 10 kHz, and 100 kHz away from
the resultant 1 MHz IF.
Test Setup Connect the equipment, shown in Figure 3-5, as fol-
lows:
1. Connect the 682XXB/683XXB DUT rear panel
10 MHz REF OUT to the BNC tee. Connect one leg
of the tee to the 682XXB/683XXB LO rear panel
10 MHz REF IN . Connect the other leg of the tee
to the Spectrum Analyzer External Reference In-
put.
2. Connect the 682XXB/683XXB DUT RF OUTPUT
to the Mixer’s R input via a 10 dB attenuator.
3. Connect the 682XXB/683XXB LO RF OUTPUT to
the Mixer’s L input.
4. Connect the Mixer’s X output to the Spectrum
Analyzer 50
W input.
3-22 682XXB/683XXB MM
PERFORMANCE SINGLE SIDEBAND
VERIFICATION PHASE NOISE TEST
10 MHz
REF IN
682XXB / 683XXB (LO)
EXTERNAL
REF INPUT
Mixer
RF OUT
L
X
R
HP 3585B
Spectrum Analyzer
BNC TEE
10 dB
Attenuator
10 MHz
REF OUT
RF OUT
682XXB / 683XXB (DUT)
Figure 3-5. Equipment Setup for Single Sideband Phase Noise Test