The MAX2370 integrated quadrature transmitter is designed for 450MHz applications. The device takes a differential I/Q baseband input and converts it up to intermediate frequency (IF) through a quadrature modulator and IF variable-gain amplifier (VGA). The signal is then routed to an external IF filter and upconverted to RF through an image-reject mixer and RF VGA. The signal is further amplified with an on-chip power amplifier (PA) driver. An IF synthesizer, an RF synthesizer, a local oscillator buffer, and an SPITM/QSPITM/MICROWIRETMcompatible, 3-wire programmable bus complete the basic functional blocks of this IC.