Chip Integrates Versatile BF/Digital Interface

摘要

As digital architectures steadily displace analog circuitry in modern communications systems, the interface between the RF and baseband/digital sections becomes ever more critical. In the AD9856 quadrature digital upcon-verter, the engineers at Analog Devices (Norwood, MA) have developed an integrated circuit (IC) that provides the flexibility to support virtually all present and future modulation formats. The IC integrates a 12-b high-speed digital-to-analog converter (DAC), a 12-b, 200-MHz direct-digital synthesizer (DDS), interpolation filters, and quadrature modulator. It may be the only RF-to-digital interface needed for present and next-generation wireless communications systems.