AD9857 是一款功能強大的可編程數字上變頻器，高速的處理速度、精確的載波
頻率和靈活的數字控制使得它廣泛應用于通信、雷達、導航等各個領域。本文介紹了該上變頻器的用法和功能，給出了與DSP 進行傳輸的接口連接和寄存器配置。結合軟件無線電的思想，設計一個可以按照用戶需要靈活更改載波頻率和調制方式的雙路音頻無線傳輸系統。
關鍵字：AD9857；數字上變頻器；獨立邊帶；軟件無線電
Abstract：AD9857 is a set of powerful programmable digital upconverter with so many
advantages. It has a high speed of processing. The carrier frequency made from inside DDS core is very precise and it is also easier and flexible to control it in digital way. It is because of so many excellent qualities that AD9857 is widely used in different kinds of fields such as communication, radar, navigation and so on. This article makes an introduction of this chip’s usages and functions. The interface used to communicate with DSP and the setting of its inside registers are also included. With the idea of software radio, the design of a double-path audio wireless transmission system which is easy to change the carrier frequency and the mode of modulation is also given.
Key words: AD9857; digital upconverter; ISB; Software Radio