Noise Parameter Analysis of SiGe HBTs for Different Sizes in the Breakdown Region

Table 4

Determined base and collector noise spectral density for different sized SiGe HBTs in the breakdown region of  V and  V. The results obtained from the presented noise model, calculation, and conventional model are compared. The variation is indicated for the results obtained from the presented model as the deviation of noise performance fitting is within 1%.

	from presented noise model (×10^−24 A^2 s)	from calculation (×10^−24 A^2 s)	from conventional noise model (×10^−24 A^2 s)
0.2 μm × 1.7 μm	5.44–5.97/42.83–43.32	5.64/43.11	6.11/43.36
0.6 μm × 1.7 μm	7.21–7.76/46.3–47.0	7.41/46.76	8.01/47.33
0.2 μm × 10.2 μm	8.54–8.90/48.87–49.36	8.86/49.12	9.41/49.89
0.6 μm × 10.2 μm	11.01–11.72/55.68–56.19	11.65/55.89	12.87/56.93

It is difficult to achieve error below 1% by the conventional noise model so that the determined values deviate from calculation results.