AD8349AREZ Analog Devices Inc, AD8349AREZ Datasheet - Page 21

• Manufacturer Part Number: AD8349AREZ
• Description: IC QUADRATURE MOD 700MHZ 16TSSOP
• Manufacturer: Analog Devices Inc

Specifications of AD8349AREZ

• Function: Modulator
• Lo Frequency: 700MHz ~ 2.7GHz
• Rf Frequency: 700MHz ~ 2.7GHz
• P1db: 5.6dBm
• Noise Floor: -156dBm/Hz
• Output Power: 5.1dBm
• Current - Supply: 150mA
• Voltage - Supply: 4.75 V ~ 5.5 V
• Test Frequency: 2.14GHz
• Package / Case: 16-TSSOP Exposed Pad, 16-eTSSOP, 16-HTSSOP
• Frequency Range: 700MHz To 2700MHz
• Rf Type: Quadrature
• Supply Voltage Range: 4.75V To 5.5V
• Rf Ic Case Style: TSSOP
• No. Of Pins: 16
• Operating Temperature Range: -40°C To +85°C
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

APPLICATIONS
3GPP WCDMA SINGLE-CARRIER APPLICATION
The interpolation filter used for the measurement of WCDMA
performance is shown in Figure 57. This third order Bessel filter
has a 3 dB bandwidth of 12 MHz. While the 3GPP single
channel bandwidth is only 3.84 MHz, this wide 3 dB bandwidth
of 12 MHz was driven by the need for a flat group delay out to
at least half the bandwidth of the baseband signal. Figure 58
shows a plot of a WCDMA spectrum at 2140 MHz using the
3 GPP Test Model 1 (64 channels active). At an output power of
–17.3 dBm, an adjacent channel power ratio (ACPR) just shy of
–69 dBc was measured.
Figure 59 shows the variation in ACPR with output power at
1960 MHz and 2140 MHz. It also shows the noise floor
measured at an offset of 30 MHz from the center of the modu-
lated WCDMA signal. From the graphs, it can be seen that there
is an optimal output power at which to operate that delivers the
best ACPR. If the output power is increased beyond that point,
the ACPR degrades as the result of increased distortion. Below
that optimum, the ACPR degrades due to a reduction in the
signal-to-noise ratio of the signal.
AD9777
–100
–110
–120
–130
–33
–40
–50
–60
–70
–80
–90
I
I
I
I
OUTB1
OUTA1
OUTA2
OUTB2
Figure 58. Single-Carrier WCDMA Spectral Plot at 2140 MHz,
including Adjacent and Alternate Channel Power Ratio
Figure 57. Single-Carrier WCDMA Application Circuit
ALT
LO
73
72
69
68
40.2Ω
40.2Ω
40.2Ω
40.2Ω
(DAC-Modulator Interconnect)
ADJ
LO
100pF
100pF
680nH
680nH
680nH
680nH
CH
270pF
270pF
CH PWR = –17.3dBm
ADJ CPR = –68.7dB
ALT CPR = –72.7dB
ADJ
UP
SPAN 24.6848MHz
240Ω
240Ω
16
15
1
2
ALT
UP
QBBP
QBBN
IBBP
IBBN
AD8349
Rev. A | Page 21 of 28
WCDMA MULTICARRIER APPLICATION
The high dynamic range of the AD8349 also permits use in
multicarrier WCDMA applications. Figure 60 shows a 4-carrier
WCDMA spectrum at 1960 MHz. At a per-carrier power of
–24.2 dBm, an ACPR of –60.4dB is achieved. Figure 61 shows
the variation in ACP and noise floor (dBc/Hz) with output
power.
Figure 59. Single-Carrier WCDMA ACPR and Noise Floor (dBm/Hz) at 30 MHz
–62
–63
–64
–65
–66
–67
–68
–69
–70
–71
–72
–100
–110
–120
–130
–30
–40
–50
–60
–70
–80
–90
–26
Carrier Offset vs. Channel Power at 1960 MHz and 2140 MHz
CH PWR = –24.2dBm
ADJ CPR = –60.4dB
ALT CPR = –63.1dB
Including Adjacent and Alternate Channel Power Ratio
Figure 60. 4-Carrier WCDMA Spectral Plot at 1960 MHz,
2140 ADJ CPR
–24
2140 NOISE
1960 NOISE
(Test Model 1 with 64 Active Channels)
–22
CHANNEL POWER (DBM)
–20
1960 ADJ CPR
–16
–14
–12
SPAN 40MHz
–10
AD8349
–8
–147
–148
–149
–150
–151
–152
–153
–154
–155
–156
–157