The AD8341 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 −4.5 dB to less than −34.5 dB, and the phase
can be shifted continuously over the entire 360° range. For maximum
gain, the AD8341 delivers an OP1dB of 8.5 dBm, an OIP3
of 17.5 dBm, and an output noise floor of −150.5 dBm/Hz,
independent of phase. It operates over a frequency range of
1.5 GHz to 2.4 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.
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 AD8341 operates off supply voltages from 4.75 V to 5.25 V
while consuming approximately 125 mA.
The AD8341 is fabricated on Analog Devices’ proprietary, high
performance 25 GHz SOI complementary bipolar IC process. It
is available in a 24-lead, lead-free LFCSP package and operates
over a −40°C to +85°C temperature range. Evaluation boards
are available.
Applications
- RF PA linearization/RF predistortion
- Amplitude and phase modulation
- Variable attenuators and phase shifters
- CDMA2000, WCDMA, GSM/EDGE linear power amplifiers
- Smart antennas
Availability
Samples part number AD8341ACP and an evaluation board, part number AD8341-EVAL, are available.
Companion Products
AD8302 - LF - 2.7GHz RF/IF Gain Phase Detector
AD8340 - RF Vector Modulator 700MHz to 1000MHz
Other Modulator / Demodulator Products
AD8345 - 250MHz to 1000MHz Low Noise RF/IF Modulator
AD8346 - 800MHz to 2.5GHz Lower Power Direct Up-Conversion Modulator
AD8347 - 800MHz to 2.7GHz Direct Conversion Demodulator
AD8348 - 50MHz to 1000MHz RF/IF Quadrature Demodulator
AD8349 - 700MHz - 2.7GHz Low Noise Direct Up Conversion Modulator
