Abstract：A monolithic SiGe Heterojunction Bipolar Transistor (HBT) Low Noise Amplifier (LNA) is designed and fabricated in this paper. Composite resistance feedback loops are adopted in this amplifier. Hence, reasonable bias conditions, good port matching and low Noise Figure (NF) are achieved simultaneously by adjusting different feedback resistor smartly. Based on the 0.35-μm Si CMOS technology, the fabrication processes for monolithic amplifier integrated chip are developed. In the fabrication process of SiGe devices, base resistance of transistor is reduced by using titanium silicon (TiSi2) deposition in order to further decrease the NF of LNA. Finally, die area of this monolithic LNA is only 0.282 mm2 due to the absence of spiral inductor which occupies most of chip area. The measurement results indicate that, in the band from 0.2 to1.2 GHz, this LNA achieves the minimum NF of 2.5 dB, the maximum gain as high as 26.7 dB, and the input and output reflections (S11, S22) of less than -7.4 dB and -10 dB, respectively.
2010, Vol. 32 
