AD8345
Rev. B | Page 18 of 20
MODULATED WAVEFORM SETUP
To evaluate the AD8345 with modulated waveforms, the setup
shown in
Figure 38 is used. A Rohde & Schwarz AMIQ signal
generator with differential outputs is used to generate the
baseband signals. For all measurements, the input level on each
baseband input pin is 0.7 V ±0.3 V peak. The output is
measured with a Rohde & Schwarz FSIQ spectrum/vector
analyzer.
+15V MAX
COM
+25V MAX
–25V MAX
HP3631
IEEE
AD8345
CHARACTERIZATION
BOARD
P1
IN
IP QP
QN
VOUT
LO
ENBL
RFOUT
IEEE
HP8648C
IEEE
PC CONTROLLER
SPECTRUM
ANALYZER
RF I/P
IEEE
FSIQ
PC CONTROL
AMIQ
IN IP QP QN
00932-038
Figure 38. Test Setup for Evaluating AD8345 with Modulated Waveforms
CDMA IS95
To measure ACPR, the I and Q input signals used are generated
with Pilot channel (Walsh Code 00), Sync channel (WC 32), Paging
channel (WC 01), and six Traffic (WC 08, 09, 10, 11, 12, 13)
channels active.
Figure 39 shows the typical output spectrum for
this configuration.
To perform EVM, Rho, phase, and amplitude balance
measurements, the I and Q input signals used are generated
with only the Pilot channel (Walsh Code 00) active.
CENTER = 880MHz SPAN = 7.5MHz
AMPLITUDE (dBm)
–10
–20
–30
–40
–50
–60
–70
–80
–90
–100
–110
00932-039
CH PWR = –12.41dBm
ACP UP = –72.9dB
ACP LOW = –72.9dB
Figure 39. Typical IS95 Output Spectrum
WCDMA 3GPP
To evaluate the AD8345 for WCDMA, the 3GPP standard is
used with a chip rate of 3.84 MHz. The plot in
Figure 40 is an
ACPR plot of the AD8345 using Test Model 1 from the 3GPP
specification with 64 channels active.
CENTER = 380MHz SPAN = 14.7MHz
AMPLITUDE (dBm)
–10
–20
–30
–40
–50
–60
–70
–80
–90
–100
–110
00932-040
CH PWR = –10.95dBm
ACP UP = –52.51dB
ACP LOW = –52.41dB
Figure 40. Typical AD8345 WCDMA 3GPP Output Spectrum
GSM
To compare the AD8345 output to the GSM transmit mask, I
and Q signals are generated using MSK modulation, GSM
differential coding, a Gaussian filter, and a symbol rate of
270.833 kHz. The transmit mask is manually generated on the
FSIQ using the GSM BTS specification for reference. The plot in
Figure 41 shows that the AD8345 meets the GSM transmit
mask requirements.
CENTER = 900MHz SPAN = 1MHz
AMPLITUDE (dBm)
0
–10
–20
–30
–40
–50
–60
–70
–80
–90
–100
00932-041
Figure 41. Typical AD8345 GSM Output Spectrum
