During the past decade, there have been considerable advances in radio frequency (RF)
communication circuit design. These advances stem from new RF architectures that were once considered to be impossible because of low integration, high power consumption, and poor process technology. In addition, the availability of high-performance, dense sub-micron CMOS technology has dramatically changed the approach to designing RF communication circuits by
enabling digital techniques.

This paper describes how integrating external components and RF circuits with the digital baseband reduces the bill-of-materials (BOM), decreases required board space, simplifies the board level design of the application, and improves manufacturability. The paper describes the
Si4700—the industry’s first radio tuner integrated circuit (IC)—in detail and explains how it leverages a digital low-IF architecture and a 100-percent CMOS process technology, resulting in a completely integrated solution.