Datasheet

Maxim Integrated │ 18
MAX2022 High-Dynamic-Range, Direct Up/
Downconversion 1500MHz to 3000MHz
Quadrature Modulator/Demodulator
www.maximintegrated.com
Pin Description (continued)
Detailed Description
The MAX2022 is designed for upconverting differential
in-phase (I) and quadrature (Q) inputs from baseband to
a 1500MHz to 3000MHz RF frequency range. The device
can also be used as a demodulator, downconverting an
RF input signal directly to baseband or an IF frequency.
Applications include single and multicarrier 1500MHz
to 3000MHz UMTS/WCDMA, LTE/TD-LTE, cdma2000,
and DCS/PCS base stations. Direct conversion architec-
tures are advantageous since they significantly reduce
transmitter or receiver cost, part count, and power con-
sumption as compared to traditional IF-based double-
conversion systems.
The MAX2022 integrates internal baluns, an LO buffer, a
phase splitter, two LO driver amplifiers, two matched dou-
ble-balanced passive mixers, and a wideband quadrature
combiner. Precision matching between the in-phase and
quadrature channels, and highly linear mixers achieves
excellent dynamic range, ACLR, 1dB compression point,
and LO and sideband suppression, making it ideal for
four-carrier WCDMA/UMTS operation.
LO Input Balun, LO Buffer, and Phase Splitter
The MAX2022 requires a single-ended LO input, with a
nominal power of 0dBm. An internal low-loss balun at
the LO input converts the single-ended LO signal to a
differential signal at the LO buffer input. In addition, the
internal balun matches the buffer’s input impedance to
50Ωovertheentirebandofoperation.
The output of the LO buffer goes through a phase splitter,
whichgeneratesasecondLOsignalthatisshiftedby90°
with respecttothe original. The 0° and 90° LO signals
drive the I and Q mixers, respectively.
LO Driver
Followingthephasesplitter,the0°and90°LOsignalsare
each amplified by a two-stage amplifier to drive the I and
Q mixers. The amplifier boosts the level of the LO signals
to compensate for any changes in LO drive levels. The
two-stage LO amplifier allows a wide input power range
for the LO drive. While a nominal LO power of 0dBm is
specified, the MAX2022 can tolerate LO level swings from
-3dBm to +3dBm.
I/Q Modulator
The MAX2022 modulator is composed of a pair of
matched double-balanced passive mixers and a balun.
The I and Q differential baseband inputs accept signals
from DC to beyond 500MHz with differential amplitudes
up to 2V
P-P
differential (common-mode input equals 0V).
The wide input bandwidth allows for direct interface with
the baseband DACs. No active buffer circuitry between
the baseband DAC and the MAX2022 is required.
TheIandQsignalsdirectlymodulatethe0°and90°LO
signals and are upconverted to the RF frequency. The
outputs of the I and Q mixers are combined through a
balun to a singled-ended RF output.
Applications Information
LO Input Drive
The LO input of the MAX2022 requires a single-ended
drive at a 1500MHz to 3000MHz frequency. It is internally
matchedto50Ω.Anintegratedbalunconvertsthesingle-
ended input signal to a differential signal at the LO buffer
differential input. An external DC-blocking capacitor is the
only external part required at this interface. The LO input
power should be within the -3dBm to +3dBm range.
PIN NAME FUNCTION
21 BBIN Baseband In-Phase Negative Input
23 RF RF Port
25 BBQN Baseband Quadrature Negative Input
26 BBQP Baseband Quadrature Positive Input
31 VCCLOQ2
Q-Channel2ndLOAmplierSupplyVoltage
33 VCCLOQ1 Q-Channel1stLOAmplierSupplyVoltage
— EP
ExposedGroundPaddle.TheexposedpaddleMUST be soldered to the
ground plane using multiple vias.