採用行為模型設計方法之超寬頻射頻前端接收器設計

Abstract

為了改善射頻電路設計流程以及系統驗證的效率，本論文提出一個可用於寬頻放大 器的行為模型計設方法。此行為模型將一放大器分成輸入介面、增益級與輸出介面三個 部份，並且可同時模擬輸入╱輸出阻抗匹配、雜訊指數、頻率響應以及非線性失真等射 頻電路的特性。為了證明此方法的可行性，本論文設計了一個寬頻放大器的行為模型， 並比較電晶體階層與型為模型的系統模擬結果，其EVM 的均方根值誤差小於0.79%，模 擬時間減少了87%。此行為模型除了能夠用來模擬一個既有的電路外，也能夠用來幫助 設計新的電路。本論文利用此行為模型設計了一個以電容性交錯藕合技術做為輸入阻抗 匹配的低雜訊放大器，並將此放大器應用於超寬頻射頻前端接收器。經由0.18-μm CMOS 製程進行電路實作，此射頻前端接收器的模擬結果，其頻寬範圍為3.1-10.6GHz，消耗 功率為11.4mW，同時具有20.9 dB的最大電壓增益、3.4dB的最低雜訊指數和-14.3dBm 的最大第三階互調線性度。

In order to improve RFIC design flow and facilitate system performance verification, an innovative behavior model of wideband amplifier is proposed. The proposed behavior model can simultaneously predict the characteristics of RF effect of input/output impedance matching, noise, frequency response and nonlinearity in one single model. To demonstrate the feasibility of the model, a wideband LNA has been designed with this model. The system simulation results show that the behavior model agrees well with the transistor level circuit iii with RMS error less than 0.79%, and 87% reduction of simulation time is achieved. The proposed behavior model can not only model an existed circuit, but also can help to design a new circuit. In this thesis, a design example of wideband LNA with capacitive cross-coupling (CCC) technique for input matching is presented. And the LNA is utilized in a receiver front-end design for UWB application. A circuit implementation in 0.18-μm CMOS process shows a 3.1-10.6GHz bandwidth. The UWB receiver front-end provides a maximum voltage conversion gain of 20.9 dB while drawing 11.4 mW from a 1.8-V supply. A double sideband noise figure as low as 3.4 dB and a maximum IIP3 of -14.3 dBm have been simulated.