User`s guide

Residual Measurement Fundamentals 7
Agilent E5505A User’s Guide 227
coupler. This isolation can be improved at the expense of signal level by
adding an attenuator between the coupler and the power splitter.
5 Connect the phase detector.
6 Adjust the phase difference at the phase detector to 90 degrees
(quadrature) either by adjusting the test frequency or by adjusting an
optional variable phase shifter or line stretcher. Quadrature is achieved
when the meter on the front panel of the test set is set to center scale.
7 Enter sideband level and offset.
8 Check quadrature and measure the phase detector constant.
9 Remove audio source.
10 Reset quadrature and measure phase noise data.
Figure 161 Carrier-to-spur ratio of non-modulated signal
Power
splitter
Phase
detector
Source
E5505a_carrier_spur_ratio_non_mod
01 Mar 04 rev 1
Optional line
stretcher
Test set
Signal
input
Ref input
<-60 dBc
RF spectrum
analyzer
}
Calibration
source
-10 dB
attenuator
-20 dB
coupler
output
Coupler
port
input
NOTE
For the system to accept the adjustment to quadrature, the meter must be within ±2 mV to
±4 mV.