Analog Devices AD8340 Service Manual

700 MHz to 1000 MHz

FEATURES

Cartesian amplitude and phase modulation
700 MHz to 1.0 GHz frequency range
Continuous magnitude control of −2 dB to −32 dB
Continuous phase control of 0° to 360°
Output third-order intercept 24 dBm
Output 1 dB compression point 11 dBm
Output noise floor −149 dBm/Hz @ full gain
Adjustable modulation bandwidth up to 230 MHz
Fast output power disable

4.75 V to 5.25 V single-supply voltage

APPLICATIONS

RF PA linearization/RF predistortion
Amplitude and phase modulation
Variable attenuators and phase shifters
CDMA2000, GSM/EDGE linear power amplifiers
Smart antennas

GENERAL DESCRIPTION

The AD8340 vector modulator performs arbitrary amplitude
and phase modulation of an RF signal. Since the RF signal path
is linear, the original modulation is preserved. This part can be
used as a general-purpose RF modulator, a variable attenu­ator/phase shifter, or a remodulator. The amplitude can be
controlled from a maximum of −2 dB to less than −32 dB, and
the phase can be shifted continuously over the entire 360° range.
For maximum gain, the AD8340 delivers an OP1dB of 11 dBm,
an OIP3 of 24 dBm, and an output noise floor of −149 dBm/Hz,
independent of phase. It operates over a frequency range of
700 MHz to 1.0 GHz.

The baseband inputs in Cartesian I and Q format control the
amplitude and phase modulation imposed on the RF input
signal. Both I and Q inputs are dc-coupled with a ±500 mV
differential full-scale range. The maximum modulation band­width is 230 MHz, which can be reduced by adding external
capacitors to limit the noise bandwidth on the control lines.

RF Vector Modulator

AD8340

FUNCTIONAL BLOCK DIAGRAM

VPRF

90°

RFIP

RFIM

0°

CMOP

Figur e 1.

Both the RF inputs and outputs can be used differentially or
single-ended and must be ac-coupled. The RF input and output
impedances are nominally 50 Ω over the operating frequency
range. The DSOP pin allows the output stage to be disabled
quickly in order to protect subsequent stages from overdrive.
The AD8340 operates off supply voltages from 4.75 V to 5.25 V
while consuming approximately 130 mA.

The AD8340 is fabricated on Analog Devices’ proprietary, high
performance 25 GHz SOI complementary bipolar IC process. It
is available in a 24-lead Pb-free LFCSP package and operates
over a −40°C to +85°C temperature range. Evaluation boards
are available.

VPS2OBBMQBBP

RFOP

RFOM

DSOPIBBMIBBP

04699-0-001

Rev. 0

Information furnished by Analog Devices is believed to be accurate and reliable.
However, no responsibility is assumed by Analog Devices for its use, nor for any
infringements of patents or other rights of third parties that may result from its use.
Specifications subject to change without notice. No license is granted by implication
or otherwise under any patent or patent rights of Analog Devices. Trademarks and
registered trademarks are the property of their respective owners.

One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: [phone]
Fax: [phone] © 2004 Analog Devices, Inc. All rights reserved.

www.analog.com

AD8340

TABLE OF CONTENTS

Specifications..................................................................................... 3

RF Frequency Range.................................................................. 11

Absolute Maximum Ratings............................................................ 4

ESD Caution.................................................................................. 4

Pin Configuration and Function Descriptions............................. 5

Typical Performance Characteristics ............................................. 6

Theory of Operation ...................................................................... 10

RF Quadrature Generator......................................................... 10

I-Q Attenuators and Baseband Amplifiers.............................. 11

Output Amplifier........................................................................ 11

Noise and Distortion.................................................................. 11

Gain and Phase Accuracy .......................................................... 11

REVISION HISTORY

6/04—Revision 0: Initial Version

Applications..................................................................................... 12

Using the AD8340 ...................................................................... 12

RF Input and Matching ............................................................. 12

RF Output and Matching .......................................................... 13

Driving the I-Q Baseband Controls......................................... 13

Interfacing to High Speed DACs.............................................. 14

CDMA2000 Application............................................................ 14

Evaluation Board............................................................................ 16

Outline Dimensions....................................................................... 20

Ordering Guide .......................................................................... 20

Rev. 0 | Page 2 of 20

AD8340

SPECIFICATIONS

V = 5 V, T = 25°C, Z = 50 Ω, f = 880 MHz, single-ended, ac-coupled source drive to RFIP through 5.6 nH series inductor, RFIM

S A O

ac-coupled through 5.6 nH series inductor to common, differential-to-single-ended conversion at output using 1:1 balun.

Table 1.

Parameter Conditions Min Typ Max Unit

OVERALL FUNCTION

Frequency Range 700 1000 MHz
Maximum Gain Maximum gain setpoint for all phase setpoints −2 dB
Minimum Gain V
Gain Control Range Relative to maximum gain 30 dB
Phase Control Range Over 30 dB control range 360 °
Gain Flatness Over any 60 MHz bandwidth 0.25 dB
Group Delay Flatness Over any 60 MHz bandwidth 10 ps

RF INPUT STAGE RFIM, RFIP (Pins 21 and 22)

Input Return Loss From RFIP to CMRF (with 5.6 nH series inductors) 20 dB

CARTESIAN CONTROL INTERFACE (I & Q) IBBP, IBBM, QBBP, QBBM (Pins 16, 15, 3, 4)

Gain Scaling 2 1/V
Modulation Bandwidth 250 mV p-p sinusoidal baseband input single-ended 230 MHz
Second Harmonic Distortion 250 mV p-p, 1 MHz, sinusoidal baseband input differential 47 dBc
Third Harmonic Distortion 250 mV p-p, 1 MHz, sinusoidal baseband input differential 45 dBc
Step Response

RF OUTPUT STAGE RFOP, RFOM (Pins 9, 10)

Output Return Loss Measured through balun 7.5 dB

f = 880 MHz

Gain Maximum gain setpoint −2 dB
Output Noise Floor Maximum gain setpoint, no input −149 dBm/Hz
P
Output IP3 f1 = 880 MHz, f2 = 877.5 MHz, maximum gain setpoint 24 dBm
ACPR

Output 1 dB Compression Point Maximum gain 11 dBm

POWER SUPPLY VPS2 (Pin 5, 6, 14); RFOP, RFOM (Pins 9, 10)

Positive Supply Voltage 4.75 5 5.25 V
Total Supply Current Includes load current 110 130 150 mA

OUTPUT DISABLE DSOP (Pin 13)

Disable Threshold 2.5 V

Maximum Attenuation DSOP = 5 V 40 dB

Enable Response Time

Disable Response Time

= V

BBI

For gain setpoint from 0.1 to 0.9
(V

For gain setpoint from 0.9 to 0.1
(V

IN

IS-95, single carrier, P

= 0 V −32 dB

BBQ

45 ns

= 0.5 V, V

BBP

= 0.55 V to 0.95 V)

BBM

47 ns

= 0.5 V, V

BBP

= 0.95 V to 0.55 V)

BBM

= 0 dBm, frequency offset = 20 MHz −147 dBm/Hz

= 0 dBm, maximum gain,

OUT

62 dBc

phase setpoint = 45°

Delay following high-to-low transition until device

15 ns

meets full specifications
Delay following low-to-high transition until device

10 ns

produces full attenuation

Rev. 0 | Page 3 of 20

AD8340

ABSOLUTE MAXIMUM RATINGS

Table 2.

Parameters Rating

Supply Voltage VPRF, VPS2 5.5 V
DSOP 5.5 V
IBBP, IBBM, QBBP, QBBM 2.5 V
RFOP, RFOM 5.5V
RF Input Power at Maximum Gain 13 dBm, re: 50 Ω

(RFIP or RFIM, Single-Ended Drive)

Equivalent Voltage 2.8 V p-p
Internal Power Dissipation 825 mW
θJA (With Pad Soldered to Board) 59 °C/W
Maximum Junction Temperature 125°C
Operating Temperature Range −40°C to +85°C
Storage Temperature Range −65°C to +150°C
Lead Temperature Range (Soldering 60 sec) 300°C

ESD CAUTION

ESD (electrostatic discharge) sensitive device. Electrostatic charges as high as 4000 V readily accumulate on the
human body and test equipment and can discharge without detection. Although this product features proprie­tary ESD protection circuitry, permanent damage may occur on devices subjected to high energy electrostatic
discharges. Therefore, proper ESD precautions are recommended to avoid performance degradation or loss of
functionality.

Stresses above those listed under Absolute Maximum Ratings
may cause permanent damage to the device. This is a stress
rating only; functional operation of the device at these or any
other conditions above those indicated in the operational
section of this specification is not implied. Exposure to absolute
maximum rating conditions for extended periods may affect
device reliability.

Rev. 0 | Page 4 of 20

AD8340

PIN CONFIGURATION AND FUNCTION DESCRIPTIONS

VPRF

CMRF

RFIP

RFIM

CMRF

2322212019

PIN 1
INDICATOR

11

10

RFOP

RFOM

CMOP

CMOP

VPRF

12

CMOP

18
17
16
15
14
13

IFLP
IFLM
IBBP
IBBM
VPS2
DSOP

04699-0-002

24

QFLP

1
2

QFLM

3

QBBP

QBBM

VPS2
VPS2

4
5
6

AD8340

TOP VIEW

(Not to Scale)

789

CMOP

Figure 2. 24-Lead Lead Frame Chip Scale Package (LFCSP)

Table 3. Pin Function Descriptions

Pin No. Mnemonic Function

1, 2 QFLP, QFLM

Q Baseband Input Filter Pins. Connect optional capacitor to reduce Q baseband channel low-pass

corner frequency.
3, 4 QBBP, QBBM Q Channel Differential Baseband Inputs.
5, 6, 14, 19, 24 VPS2, VPRF Positive Supply Voltage. 4.75 V − 5.25 V.
7, 8, 11, 12, 20, 23 CMOP, CMRF Device Common. Connect via lowest possible impedance to external circuit common.
9, 10 RFOP, RFOM Differential RF Outputs. Must be ac-coupled. Differential impedance 50 Ω nominal.
13 DSOP Output disable. Pull high to disable output stage.
15, 16 IBBM, IBBP I Channel Differential Baseband Inputs.
17, 18 IFLM, IFLP

I Baseband Input Filter Pins. Connect optional capacitor to reduce I baseband channel low-pass

corner frequency.
21, 22 RFIM, RFIP Differential RF Inputs. Must be ac-coupled. Differential impedance 50 Ω nominal.

Rev. 0 | Page 5 of 20

AD8340

TYPICAL PERFORMANCE CHARACTERISTICS

0

–5

–10

–15

–20

GAIN (dB)

–25

–30

–35

–40

0.1

0 0.3 0.5 0.9 1.00.80.70.60.40.2

Figure 3. Gain Magnitude vs. Gain Setpoint at Different Phase Setpoints,

4
3

2
1

0
–1
–2
–3
–4
–5

GAIN CONFORMANCE ERROR (dB)

–6
–7

0 0.1 1.00.2 0.3 0.4 0.5 0.6 0.7 0.8

Figure 4. Gain Conformance E rror vs. Gain Setpoint at

0
–2
–4
–6
–8

–10
–12

GAIN (dB)

–14
–16

–18
–20
–22
–24

Figure 5. Gain Magnitude vs. Phase Setpoint at Different Gain Setpoints

PHASE SETPOINT = 0°

PHASE SETPOINT = 270°

PHASE SETPOINT = 180°

GAIN SETPOINT

RF Frequency = 880 MHz

PHASE SETPOINT = 135°
PHASE SETPOINT = 45°

PHASE SETPOINT = 90°
PHASE SETPOINT = 0°

PHASE SETPOINT = 315°

PHASE SETPOINT = 270°

PHASE SETPOINT = 180°

PHASE SETPOINT = 225°

GAIN SETPOINT

Different Phase Setpoints

GAIN SETPOINT = 1.0

GAIN SETPOINT = 0.5

GAIN SETPOINT = 0.1

45

PHASE SETPOINT (Degrees)

PHASE SETPOINT = 90°

0.9

315270 36018090 135 2250

04699-0-003

04699-0-004

04699-0-005

0.4

0.2

0.0
–0.2
–0.4
–0.6
–0.8
–1.0
–1.2
–1.4
–1.6

GAIN CONFORMANCE ERROR (dB)

–1.8
–2.0

GAIN SETPOINT = 0.1

45 315270 36018090 135 2250

PHASE SETPOINT (Degrees)

GAIN SETPOINT = 1.0

GAIN SETPOINT = 0.5

Figure 6. Gain Conformance Error vs. Phase Setpoint at Diffe rent Gain Setpoints

360
330
300
270
240
210
180

GAIN SETPOINT = 0.1

150

PHASE (Degrees)

120

90
60
30

0

0 30 60 90 120 150 180 210 240 270 300 330 360

GAIN SETPOINT = 1.0

GAIN SETPOINT = 0.5

PHASE SETPOINT (Degrees)

Figure 7. Phase vs. Phase Setpo int at Different Gain Setpoi nts

6

4

2

0

–2

–4

–6

PHASE ERROR (Degrees)

–8

–10

–12

0 45 90 135 360180 225 270 315

GAIN SETPOINT = 0.1

GAIN SETPOINT = 1.0

GAIN SETPOINT = 0.5

04699-0-008

PHASE SETPOINT (Degrees)

Figure 8. Phase Error vs. Phase Setpoint at D ifferent Gain Setpoints

04699-0-006

04699-0-007

Rev. 0 | Page 6 of 20