针对当前无线通信系统对高效射频功放技术的实际需求, 梳理了射频开关功放 (SMPA)技术的研究进展, 同时对比了不同结构射频 SMPA的应用特性。在此基础上, 首次采用多比特带通 Delta–Sigma调制器 (BPDSM)和多电平 SMPA, 提出一种新的基于电压型 D-类(VMCD)功放的全数字发信机架构, 并基于现场可编程逻辑门阵列 (FPGA)器件和分立元件实现了全数字发信机。硬件测试结果表明, 30~88 MHz超短波频率下, 系统平均输出功率为 15.2 W, 效率达到 60%以上。

Focusing on the application requirements on high-efficiency radio frequency poweramplifier in wireless communicationsystem, the studies and applications of radio frequency Switch -Mode Power Amplifier(SMPA) technology are surveyed. The application characteristics of SMPA under different structures are also compared. By using the multi-bit Band-Pass Delta-Sigma Modulator(BPDSM) and multi-level SMPA, a novel full-digital transmitter structure based on Voltage-Mode Class-D(VMCD) power amplifier is proposed. And the full-digital transmitter is implemented based on the Field Programmable Gate Array(FPGA) and lump components. The hardware measurement results show that the transmitter achieves a power efficiency greater than 60% around an average output power of 15.2 W in 30-88 MHz frequency.