|
|
PDF AD8340 Data sheet ( Hoja de datos )
| Número de pieza | AD8340 | |
| Descripción | RF Vector Modulator | |
| Fabricantes | Analog Devices | |
| Logotipo |  |
|
Hay una vista previa y un enlace de descarga de AD8340 (archivo pdf) en la parte inferior de esta página. Total 20 Páginas | ||
|
No Preview Available !
Data Sheet
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 at 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. Because 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 fre-
quency 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 band-
width is 230 MHz, which can be reduced by adding external
capacitors to limit the noise bandwidth on the control lines.
700 MHz to 1000 MHz
RF Vector Modulator
AD8340
FUNCTIONAL BLOCK DIAGRAM
VPRF
QBBP QBBM
VPS2
RFIP
RFIM
90°
0°
RFOP
RFOM
CMOP
IBBP IBBM
Figure 1.
DSOP
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 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 using the Analog Devices, Inc.
proprietary, high performance 25 GHz SOI complementary
bipolar IC process. It is available in a 24-lead RoHS-compliant
LFCSP package and operates over a −40°C to +85°C tempera-
ture range. Evaluation boards are available.
Rev. C
Document Feedback
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.
Trademarksandregisteredtrademarksarethepropertyoftheirrespectiveowners.
One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: 781.329.4700 ©2004–2014 Analog Devices, Inc. All rights reserved.
Technical Support
www.analog.com
1 page  
Data Sheet
PIN CONFIGURATION AND FUNCTION DESCRIPTIONS
AD8340
QFLP 1
QFLM 2
QBBP 3
QBBM 4
VPS2 5
VPS2 6
AD8340
TOP VIEW
(Not to Scale)
18 IFLP
17 IFLM
16 IBBP
15 IBBM
14 VPS2
13 DSOP
Table 3. Pin Function Descriptions
Pin No.
Mnemonic
1; 2 QFLP; QFLM
3; 4
5, 6, 14; 19, 24
7, 8, 11, 12; 20, 23
9; 10
13
15; 16
17; 18
QBBP; QBBM
VPS2; VPRF
CMOP; CMRF
RFOP; RFOM
DSOP
IBBM; IBBP
IFLM; IFLP
21; 22
RFIM; RFIP
EPAD
NOTES
1. THE EXPOSED PAD MUST BE CONNECTED TO GROUND
VIA A LOW IMPEDANCE PATH.
Figure 2. Pin Configuration
Description
Q Baseband Input Filter Pins. Connect optional capacitor to reduce Q baseband channel low-pass
corner frequency.
Q Channel Differential Baseband Inputs.
Positive Supply Voltage, 4.75 V to 5.25 V.
Device Common. Connect via lowest possible impedance to external circuit common.
Differential RF Outputs. Must be ac-coupled. Differential impedance 50 Ω nominal.
Output Disable. Pull high to disable output stage.
I Channel Differential Baseband Inputs.
I Baseband Input Filter Pins. Connect optional capacitor to reduce I baseband channel low-pass
corner frequency.
Differential RF Inputs. Must be ac-coupled. Differential impedance 50 Ω nominal.
Exposed Pad. The exposed pad must be connected to ground via a low impedance path.
Rev. C | Page 5 of 20
5 Page 
Data Sheet
I-Q ATTENUATORS AND BASEBAND AMPLIFIERS
The proprietary linear-responding attenuator structure is an
active solution with differential inputs and outputs that offer
excellent linearity, low noise, and greater immunity from mis-
matches than other variable attenuator methods. The gain, in
linear terms, of the I and Q channels is proportional to its control
voltage with a scaling factor designed to be 2/V, that is, a full-scale
gain setpoint of 1.0 (−2 dB) for VBBI (Q) of 500 mV. The control
voltages can be driven differentially or single-endedly. The
combination of the baseband amplifiers and attenuators allows
for maximum modulation bandwidths in excess of 200 MHz.
OUTPUT AMPLIFIER
The output amplifier accepts the sum of the attenuator outputs
and delivers a differential output signal into the external load.
The output pins must be pulled up to an external supply,
preferably through RF chokes. When the 50 Ω load is taken
differentially, an OP1dB of 11 dBm and OIP3 of 24 dBm are
achieved at 880 MHz. The output can be taken in single-ended
fashion, albeit at lower performance levels.
NOISE AND DISTORTION
The output noise floor and distortion levels vary with the gain
magnitude but do not vary significantly with the phase. At the
higher gain magnitude setpoints, the OIP3 and the noise floor
vary in direct proportion with the gain. At lower gain magni-
tude setpoints, the noise floor levels off while the OIP3 continues
to vary with the gain.
AD8340
GAIN AND PHASE ACCURACY
There are numerous ways to express the accuracy of the AD8340.
Ideally, the gain and phase should precisely follow the setpoints.
Figure 4 illustrates the gain error in decibels (dB) from a best fit
line, normalized to the gain measured at the gain setpoint = 1.0,
for the different phase setpoints. Figure 6 shows the gain error
in a different form; the phase setpoint is swept from 0° to 360°
for different gain setpoints. Figure 8 and Figure 22 show analo-
gous errors for the phase error as a function of gain and phase
setpoints. The accuracy clearly depends on the region of operation
within the vector gain unit circle. Operation very close to the
origin generally results in larger errors as the relative accuracy
of the I and Q vectors degrades.
RF FREQUENCY RANGE
The frequency range on the RF input is limited by the internal
polyphase quadrature phase-splitter. The phase-splitter splits
the incoming RF input into two signals, 90° out of phase, as
previously described in the RF Quadrature Generator section.
This polyphase network has been designed to ensure robust
quadrature accuracy over standard fabrication process
parameter variations for the 700 MHz to 1 GHz specified RF
frequency range. Using the AD8340 as a single-sideband
modulator and measuring the resulting sideband suppression is
a good gauge of how the quadrature accuracy is maintained
over RF frequency. A typical plot of sideband suppression from
500 MHz to 1.5 GHz is shown in Figure 28. The level of sideband
suppression degradation outside the 700 MHz to 1 GHz specified
range is subject to manufacturing process variations.
0
–5
–10
–15
–20
–25
–30
–35
500 600 700 800 900 1000 1100 1200 1300 1400 1500
FREQUENCY (MHz)
Figure 28. Sideband Suppression vs. Frequency
Rev. C | Page 11 of 20
11 Page | ||
| Páginas | Total 20 Páginas | |
| PDF Descargar | [ Datasheet AD8340.PDF ] | |
Hoja de datos destacado
| Número de pieza | Descripción | Fabricantes |
| AD834 | 500 MHz Four-Quadrant Multiplier | Analog Devices |
| AD8340 | RF Vector Modulator | Analog Devices |
| AD8341 | 1.5GHz to 2.4GHz RF Vector Modulator | Analog Devices |
| AD8342 | Active Receive Mixer Low Frequency to 3.8 GHz | Analog Devices |
| Número de pieza | Descripción | Fabricantes |
| SLA6805M | High Voltage 3 phase Motor Driver IC. |
 Sanken |
| SDC1742 | 12- and 14-Bit Hybrid Synchro / Resolver-to-Digital Converters. |
Analog Devices |
|
DataSheet.es es una pagina web que funciona como un repositorio de manuales o hoja de datos de muchos de los productos más populares, |
| DataSheet.es | 2020 | Privacy Policy | Contacto | Buscar |