HPMX-2005 Single and
Double Sideband
Performance
Single sideband (SSB) and double
sideband (DSB) tests are some-
times used to evaluate modulator
performance. Typical SSB and
DSB output spectrum graphs for
the HPMX-2005 are shown in fig-
ures 25 and 26 below. Figure 27
shows the test equipment setup
used to generate this information.
For accurate measurements of
modulator performance and LO
suppression, the phase shift pro-
vided by the I and Q signal genera-
tors must be very close to 90
degrees and the amplitude of the
two signals must be matched to
within a few millivolts. The I,Q
signal generator must put out low
distortion signals or the spectrum
analyzer will show high harmonic
levels that reflect the performance
of the signal generator, not the
modulator.
HPMX-2005 Typical Sideband Performance Data
V
CC
= 5 V, LO = -12 dBm, V
Iref
= V
Qref
= 2.5 V, V
Imod
= V
Iref
+ 0.75 V sin(2πf
n
t), V
Qmod
= V
Qref
+ 0.75 V cos(2πf
n
t) for
SSB, V
Imod
= V
Qmod
= V
Qref
+ 0.75 V cos(2πf
n
t) for DSB, f
n
= 25 kHz, T
A
= 25°C
Symbol
P
LSB
LO
leak
P
USB
IM
3
0
Parameters and Test Conditions
Lower Sideband Power Output
LO Suppression
Upper Sideband Power Output
3rd Order Intermodulation Distortion Level
0
Units
dBc
dBc
dBm
dBc
SSB
-8
33
-38
NA
DSB
-11
30
-11
33
OUTPUT POWER (dBm)
OUTPUT POWER (dBm)
-20
-20
-40
-40
-60
-60
-80
-80
99.9
99.95
100
100.05
100.1
99.9
99.95
100
100.05
100.1
FREQUENCY (MHz)
FREQUENCY (MHz)
Figure 25. Single Sideband Output Spectrum.
Figure 26. Double Sideband Output Spectrum.
7-61
AGILENT [ AGILENT TECHNOLOGIES, LTD. ]
