General Description

The MAX2021 low-noise, high-linearity, direct upconversion/downconversion quadrature modulator/demodulator is designed for RFID handheld and portal readers, as well as single and multicarrier 650MHz to 1200MHz GSM/EDGE, cdma2000?, WCDMA, and iDEN? base-station applications. Direct conversion architectures are advantageous since they significantly reduce transmitter or receiver cost, part count, and power consumption as compared to traditional IF-based double conversion systems.

In addition to offering excellent linearity and noise performance, the MAX2021 also yields a high level of component integration. This device includes two matched passive mixers for modulating or demodulating in-phase and quadrature signals, two LO mixer amplifier drivers, and an LO quadrature splitter. On-chip baluns are also integrated to allow for single-ended RF and LO connections. As an added feature, the baseband inputs have been matched to allow for direct interfacing to the transmit DAC, thereby eliminating the need for costly I/Q buffer amplifiers.

The MAX2021 operates from a single +5V supply. It is available in a compact 36-pin TQFN package (6mm x 6mm) with an exposed pad. Electrical performance is guaranteed over the extended -40°C to +85°C temper ature range.

Features

? 650MHz to 1200MHz RF Frequency Range

? Scalable Power: External Current-Setting

?? Resistors Provide Option for Operating Device in

?? Reduced-Power/Reduced-Performance Mode

? 36-Pin, 6mm x 6mm TQFN Provides High Isolation in a Small Package

Modulator Operation:

? Meets 4-Carrier WCDMA 65dBc ACLR

? +21dBm Typical OIP3

? +58dBm Typical OIP2

? +16.7dBm Typical OP1dB

? -32dBm Typical LO Leakage

? 43.5dBc Typical Sideband Suppression

? -174dBm/Hz Output Noise Density

? DC to 550MHz Baseband Input Allows a Direct Launch DAC Interface, Eliminating the Need for Costly I/Q Buffer Amplifiers

? DC-Coupled Input Allows Ability for Customer Offset Voltage Control

Demodulator Operation:

? +35.2dBm Typical IIP3

? +76dBm Typical IIP2

? > 30dBm IP1dB

? 9.2dB Typical Conversion Loss

? 9.3dB Typical NF

? 0.06dB Typical I/Q Gain Imbalance

? 0.15° I/Q Typical Phase Imbalance

Applications

?? RFID Handheld and Portal Readers

?? Single and Multicarrier WCDMA 850 Base Stations

?? Single and Multicarrier cdmaOne? and cdma2000 Base Stations

?? GSM 850/GSM 900 EDGE Base Stations

?? Predistortion Transmitters and Receivers

?? WiMAX Transmitters and Receivers

?? Fixed Broadband Wireless Access

?? Military Systems

?? Microwave Links

?? Digital and Spread-Spectrum Communication Systems

?? Video-on-Demand (VOD) and DOCSIS Compliant Edge QAM Modulation

?? Cable Modem Termination Systems (CMTS)