论文部分内容阅读
用金属有机化学汽相淀积法(MOCVD)研制出了低噪声HEMTAlGaAs/GaAs异质结器件。这种HEMT的栅长为0.5μm、栅宽为200μm。室温下,频率为12GHz时,达到的最小噪声系数为0.83dB,相应增益为12.5dB。测量也证实了栅键合点的数目对不同栅宽的噪声系数影响的计算结果。在低温下工作时,观察到器件的噪声系数显著提高,特别是与常规GaAsMESFET相比,更是如此。一个为DBS接收系统设计的二极放大器,其初级使用了HEMT,在11.7～12.2GHz的范围内噪声系数低于2.0dB。
Low-noise HEMTAlGaAs / GaAs heterojunction devices have been developed by metalorganic chemical vapor deposition (MOCVD). This HEMT has a gate length of 0.5 μm and a gate width of 200 μm. At room temperature, the minimum noise figure reached at a frequency of 12 GHz is 0.83 dB with a corresponding gain of 12.5 dB. The measurement also confirmed the calculation result of the influence of the number of gate bonding points on the noise figure of different gate widths. When operating at low temperatures, a significant increase in the noise figure of the device is observed, especially when compared to conventional GaAsMESFETs. A diode amplifier designed for a DBS receiver system uses a HEMT primary, with a noise figure of less than 2.0 dB over a range of 11.7 to 12.2 GHz.