| In recently years,with the rapidly development of the wireless communication technology,the higher performance requirements for the communication receiving system have been put forward. High-temperature superconducting(HTSC) receiver has become a hot spot for its high sensitivity and high selectivity. In the civil field, it can effectively expand the cover ability and communication capacity of the communication base station and also improve the anti-jamming ability. In the military field, for the excellent ability of the weak single detection, the HTSC receiver can improve the reconnaissance capability of the receive system. As the first active device of the HTSC receive front-end, the noise figure of the cryogenic low noise amplifier is very important to the sensitivity of the receiver. Therefore, the study of the cryogenic low noise amplifier with very low noise figure is very important to the receiver.Firstly, this thesis introduced the history and Development status of the low noise amplifier(LNA). And then the operating principle and design method were presented. Thirdly, two LNAs using in the High-temperature superconducting(HTSC) receive frontend adopting the pseudomorphic high electron mobility transistor(pHEMT) were designed and fabricated. The measured result and performance analysis were presented at last.In this thesis, the pHEMT ATF-54143 of Agilent Company is adopted to design the LNAs. The radio frequency circuits simulator ADS was used to design and simulate the performance of the LNAs, including of the bias circuit, the stability and the input/output matching network. Then a series negative feedback and parallel negative feedback were introduced to ensure the LNA stably operating and low noise within a very broad frequency range. Finally the LNAs were fabricated and measured. The LNAs were measured in the low-temperature of liquid nitrogen. The measured results indicated that the performance of the two cryogenic LNAs can meet the requirements of our project. |
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