Design Of A 2.4GHz Power Amplifier

With the rapid development of wireless communications and low power embedded technology, wireless sensor network (WSN) appeared in the stage of history. In today’s work of science, the application of wireless sensor networks is widely. However, due to the practical application of wireless sensor network has not had the expected low costs and low power consumption, it is meaningful to make the research and implementation of low cost, low power consumption of wireless sensor network.The topic of this thesis is the research and design of power amplifier in WSN transmitter. This paper uses TSMC 0.18μm CMOS technology to implement the design of power amplifier. This paper mainly studies the application of power amplifier in WSN and this power amplifier can be amplitude modulated, which can improve the linearity. This paper uses two stages class-A power-amplifiers driving a power stage of class-E power amplifier, of which supplied voltage can be stability DC voltage or a low frequency amplitude modulated voltage that can improve the linearity. When this chip is tested, the bond wire inductance between source pad and PCB should be considered. The differential structure can reduce the effect of source inductance on the circuit. This design works on 2.4GHz, and the circuit uses low voltage power supply of 1V. The post-simulation shows that the maximum output power is higher than 14dBm, and the average output power is near 13dBm. S11 at 2.4GHz is lower than-20dB, and S22 is lower than zero. The power added efficiency is up to 45%. The chip area is 1.1×0.78mm2. These results achieve requirements of WSN, so the output matching network can be saved. Thereby the structure reduces the area. This structure’s advantages are simple structure, high efficiency, small area, and low cost, which can be used in WSN polar transmitter. The test results show that when the supply voltage is 1V, the max output power is about from 5dBm to 8dBm, and the max PAE is 19%. When the input power is-10dBm, the S11 is lower than-23dB at 2.4GHz, and S22 is lower than-9dB at 2.4GHz. The design objectives have been achieved.This design has high efficiency and meets the requirements of WSN. Simple structure reduces the transmitter area and the power consumption. At the same time, due to the simple structure, this power amplifier can be amplitude modulation and multilevel strobe, which can be used in multi-band polar transmitter with large output power.