DESCRIPTION
The LT®5503 is a front-end transmitter IC designed for low voltage operation. The IC contains a high frequency quadrature modulator with a variable gain amplifier (VGA) and a balanced mixer. The modulator includes a precision 90° phase shifter which allows direct modulation of an RF signal by the baseband I and Q signals.

FEATURES
■ Single 1.8V to 5.25V Supply
■ Direct IQ Modulator with Integrated 90° Phase Shifter*
■ Four Step RF Power Control
■ 120MHz Modulation Bandwidth
■ Independent Double-Balanced Mixer
■ Modulation Accuracy Insensitive to Carrier Input Power
■ Modulator I/Q Inputs Internally Biased
■ Available in 20-Lead FE Package

APPLICATIONS
■ IEEE 802.11 DSSS and FHSS
■ High Speed Wireless LAN (WLAN)
■ Wireless Local Loop (WLL)
■ PCS Wireless Data
■ MMDS