Design And Implementation Of C Band Cryogenic Low Noise Wideband Amplifier

With the development of microwave technology, we require the measuring system can work at extremely low temperature. Especially in the field of semiconductor quantum dot, We need two LNA in the measuring system about coupling between resonantor and quantum dot. One should work at room temperature and the other should work at4K temperature. Because of the very week signal of quantum dot, the amplifier should not only provide enough power gain but also restrain noise. We also require the amplifier have a wide band to adapt to the change of resonant frequency.This article introduces the significance of developing a C-band cryogenic low noise wideband amplifier. And then it introduces the basic theory and the design method about the cryogenic low noise wideband amplifier. This article also introduces the technology of de-embedding S-parameter to correct the deviation between simulation and measurement. In the end this article introduces the method of designing the PCB layout and metal-shielded and the result of the measurement at room temperature and4K temperature.This article presents a C-band cryogenic low noise wideband amplifier which are with three-stage single-ended architecture. The LNA achieves performance that gain is about30.7±dB, the input and output return loss is less than-10dB, the noise figure is less than1.6dB within frequency band from5GHz to6.5GHz at room temperature. By adjusting the DC bias, the gain could increase to34.3±1.3dB at4K temperature.