目 录1 系统设计........................................................................11.1 设计要求....................................................................11.1.1 任务....................................................................11.1.2 要求....................................................................11.1.3 说明....................................................................11.2 总体设计方案................................................................21.2.1 设计思路................................................................21.2.2 方案论证与比较..........................................................21.2.3 系统组成................................................................62 单元硬件电路设计................................................................82.1 发射部分电路的设计..........................................................82.1.1AD9951(DDS)的原理.......................................................82.1.2 功率放大电路设计.......................................................112.2 接收部分电路的设计.........................................................122.2.1CXA1691BM 芯片..........................................................122.2.2 高放选频回路的设计.....................................................142.2.3 本机振荡器的设计.......................................................152.2.4 中频窄带滤波器.........................................................152.2.5FSK 接收解调模块设计....................................................152.3 抗干扰措施.................................................................163 软件设计.......................................................................183.1 发射机主控单片机拼音输入法的实现过程.......................................183.1.1T9 拼音输入法的软件流程：...............................................183.1.2 硬字库的制作与使用方法：...............................................183.1.3T9 拼音输入的实现：...........................
