Influence Of Parastic Parameter On RF Power Amplifier

With the development of Radio Frequency Communication,the signal with higher frequency and higher speed propose a greater challenge to RF circuit.RF power amplifiers as an important modules of wireless communication systems, it's role is to provide the adequate power for transmitter antenna and to reject the interference of other modules in wireless systems. With the increasing frequency of the signal, more and more parasitic effects also will be increased in RF integrated circuits.Nowdays, parasitic parameters on the performance of RF integrated circuit chips has not be ignored.Therefore, it is particularly important to consider the parasitic parameters in RF power amplifier design.According to the need of RF power amplifier which come from the project of multimedia digital conferencing system based on 2.4GHz WLAN, and also considering the stability of RF chip and cost constraints,the paper use the TSMC 0.18um RF CMOS Technology to design a RF power ampilifier.First of all, the paper introduce the characteristics of CMOS technology and the development of RF power amplifier;Then study the general theory of parasitic parameters and the common parasitic effects in CMOS technology. At the end focus on the specific design process of RF power amplifier.The circuit adopt the third-stage amplifier structure, divided into the input stage, gain stage and output stage. First design the matching network of input and output stage and that between them using load-pull method; Second design the amplifying circuit using the cascade structure and common source amplifier based on differential structure; Third show the simulation results of performance and the design of the chip layout; Last finish the verification of layout rules and circuit, and also the extraction of parasitic.The simulation results shows that in the condition of 2.4GHz working frequency and 3.3V working voltage,The maximum output power is 19.892 dBm, at ldB compression point, the PAE is 19.63% and the output power is 18.92 dBm. its power gain is 20 dB .the system linearity is well.These results indicate that the performance of improved Power Amplifier meets the design requirements of the multimedia digital conferencing system. It ensure that no distortion of audio signal transmission.