AD8346
Rev. A | Page 17 of 20
CDMA SETUP
For evaluating the AD8346 with CDMA waveforms, the setup
shown in
Figure 35 was used. This is essentially the same setup
as that used for the single sideband characterization, except that
the AFG2020 was replaced with the AWG2021 for providing the
I and Q input signals, and the spectrum analyzer used to monitor
the output was changed to an FSEA30 Rohde & Schwarz analyzer
with vector demodulation capability. The I/Q input signals for
these measurements were IS95 baseband signals generated with
Tektronix I/Q SIM software and downloaded to the AWG2021.
For measuring ACPR, the I/Q input signals used were generated
with Pilot (Walsh Code 00), Sync (WC 32), Paging (WC 01),
and 6 Traffic (WC 08, 09, 10, 11, 12, 13) channels active. The
I/Q SIM software was set for 32× oversampling and was using a
BS equifilter.
Figure 36 shows the typical output spectrum for
this configuration. The ACPR was measured 885 kHz away
from the carrier frequency.
For performing EVM, Rho, phase, and amplitude balance
measurements, the I/Q input signals used were generated with
only the pilot channel (Walsh Code 00) active. The I/Q SIM
software was set for 32× oversampling using a CDMA equifilter.
VPS1
VN
GND
VP
AD8346
MOTHERBOARD
I IN
Q
IN
D1 D2 D3
P1 IN IP QP QN
IEEE
34901 34907 34907
D1 D2 D3
HP34970A
AD8346
EVAL BOARD
P1
IN
IP QP
QN
LO
ENBL
VOUT
RFOUT
IEEE
HP8648C
+15V MAX
COM
+25V MAX
–25V MAX
IEEE
HP3631
IEEE
PC CONTROLLER
FSEA30
RF I/P
IEEE
SPECTRUM
ANALYZER
OUTPUT 1
OUTPUT
2
IEEE
TEKAFG2020
ARB FUNC. GEN
05335-035
Figure 35. Evaluation Board CDMA Test Setup
–20
CENTER 1.9GHz
–30
–40
–50
–60
–70
–80
–90
100
110
120
187.5kHz/ SPAN 1.875MHz
CH PWR = –20.7dBm
ACP UPR = –71.8dBc
ACP LWR = –71.7dBc
05335-036
Figure 36. Typical CDMA Output Spectrum
