Abstract: Switching power amplifier has higher efficiency than the traditional linear power amplifier. Class-E power amplifier is widely used because of its relatively higher efficiency and easier implementation, but it cannot achieve adequate output power and efficiency at low frequency. Class-E type matching is utilized at higher band（433 MHz） while the amplifier is matched in a novel square wave way at lower（315 MHz, 230 MHz） band. The simulation and layout are based on Cadence software, the designed amplifier can achieve 20 dBm output power with 40% drain efficiency over the entire bands using the same on-chip circuits. At the same time, the output power can be digitally controlled by changing the width of the output transistor.

Key words: multi-band, power control, CMOS, switched, power amplifier

摘要： 开关类功率放大器相对于传统的线性功率放大器有更高的效率，其中E类开关功率放大器由于其高效、易于实现等特点被广泛运用，但在低频率时E类功率放大器难以达到足够的输出功率和效率。设计实现的多频段开关功率放大器在高频段（433 MHz）采用E类匹配方式，在较低的频段（315 MHz、230 MHz）采用新颖的方波匹配。在Cadence软件平台下进行仿真及版图绘制，结果显示该多频段开关功率放大器各频段都实现了20 dBm的输出功率，漏极效率均达到40%，同时，通过控制晶体管尺寸，可以对输出功率进行数字控制。

关键词: 多频段, 功率可控, 金属氧化为半导体, 开关类, 功率放大器