Transistors are nonlinear devices, which can produce nonlinear distortion in amplifier while amplifying signals. For weak nonlinear distortion, the expressions of total harmonic distortion (THD), the second order in...Transistors are nonlinear devices, which can produce nonlinear distortion in amplifier while amplifying signals. For weak nonlinear distortion, the expressions of total harmonic distortion (THD), the second order intermodulation distortion(IM2 ), the third order intermodulation distortion(IM 3) and intercept point(IP 3) are deduced. With the aid of software Multisim, we simulate transistor common emitter amplifier, transistor common emitter amplifier with resistor in emitter, differential amplifier and differential amplifier with resistor between emitters. The simulational results and theoretical analyses are almost the same.展开更多
In this paper, an envelope Hammerstein （EH） model is introduced to describe dynamic input -output characteristics of RF power amplifiers. In the modeling approach, we use a new truncation method and an established n...In this paper, an envelope Hammerstein （EH） model is introduced to describe dynamic input -output characteristics of RF power amplifiers. In the modeling approach, we use a new truncation method and an established nonlinear time series method to determine model structure. Then, we discuss the process of model parameter extraction in detailed. Finally, a 2 W WCDMA power amplifier is measured to verify the performance of EH model, and good agreement between model output and measurement result shows our model can accurately predict output characteristic of the power amplifier.展开更多
为解决传统功率放大器在管壳外部进行谐波匹配,导致谐波短路传输相位不一致和谐波、基波匹配电路互相影响的问题,基于0.25μm GaN HEMT工艺,对C波段高效率预匹配功率放大器进行研究。功率放大器管壳内部HEMT输入端采用键合线和瓷片电容...为解决传统功率放大器在管壳外部进行谐波匹配,导致谐波短路传输相位不一致和谐波、基波匹配电路互相影响的问题,基于0.25μm GaN HEMT工艺,对C波段高效率预匹配功率放大器进行研究。功率放大器管壳内部HEMT输入端采用键合线和瓷片电容形成T型匹配网络来提升输入阻抗,以HEMT输出端键合线和瓷片电容分别作为电感和电容进行串联,使HEMT输出端对二次谐波短路,控制器件的电压和电流波形,提高放大器的漏极效率。管壳外部利用微带线进行阻抗变换,将输入输出阻抗匹配到50Ω。经测试,GaN HEMT功率放大器在5.8 GHz下饱和输出功率、漏极效率和功率增益分别为48.7 dBm、72%和11.3 dB。展开更多
文摘Transistors are nonlinear devices, which can produce nonlinear distortion in amplifier while amplifying signals. For weak nonlinear distortion, the expressions of total harmonic distortion (THD), the second order intermodulation distortion(IM2 ), the third order intermodulation distortion(IM 3) and intercept point(IP 3) are deduced. With the aid of software Multisim, we simulate transistor common emitter amplifier, transistor common emitter amplifier with resistor in emitter, differential amplifier and differential amplifier with resistor between emitters. The simulational results and theoretical analyses are almost the same.
文摘In this paper, an envelope Hammerstein （EH） model is introduced to describe dynamic input -output characteristics of RF power amplifiers. In the modeling approach, we use a new truncation method and an established nonlinear time series method to determine model structure. Then, we discuss the process of model parameter extraction in detailed. Finally, a 2 W WCDMA power amplifier is measured to verify the performance of EH model, and good agreement between model output and measurement result shows our model can accurately predict output characteristic of the power amplifier.
