Transmission Line Modeling And Its Application In Power Amplifier

With the rapid development of modern communication technology,requirements of communication system are getting higher and higher.With miniaturization and low power consumption is the two important goals of its development.The lack of high-quality on-chip passive components is a bottleneck in the development of integrated circuits.Transmission lines as an important passive component has played a very important role in the design of the circuit.Because in the circuit layout design,it will use a lot of transmission lines,so the simulation results of circuit will generally has a large difference with the test results.And as the circuit operating frequency is getting higher and higher,the transmission lines in the integrated circuit design will be more important.So transmission modeling has a great significance in the development of integrated circuits.In this paper,the transmission lines of top-level metal in CSMC 0.18?m RF CMOS process are modeled.The kinds of transmission lines to be modeled are interconnects,microstrip lines,and coupling lines.When model transmission lines,using electromagnetic field simulation software(ADS Momentum)on the transmission line layout,and the S parameters are processed to extract the component parameters in the model circuit.The modeling results of RLGC and trapezoidal structures are used to model and compare the modeling results of these two model circuits.Since the trapezoidal structure has better compatibility with the SPICE model than the RLGC structure,so the trapezoidal structure model circuit was choose.The three kinds of transmission lines are streamer and tested,and the transmission lines are modeled according to the test results.The trapezoidal structure model circuits of three transmission lines are obtained.The transmission line modeling method is applied to the power amplifier design,compared The post-simulation results without transmission line model and the post-simulation results with transmission line model,the power gain of the circuit is reduced from 26.45dB to 24.93dB,the output 1dB compression point is increased from 11.542dBm to 12.2091dBm,and the 3dB bandwidth of the circuit is changed from 5.436?6.603GHz to 5.038?6.313GHz,the results show that the transmission line effect on the 6GHz power amplifier performance has a more significant impact,indicating the need for transmission line modeling.The transmission line model designed in this paper has been embedded in PDK of CSMC 0.18?m RF CMOS process and can be applied to the design of RF circuit.