ABSTRACT
The 1/f noise characteristics and mechanisms of GaAs/AlGaAs HBT’s are studied using conventional short circuit current measurements ( S I C ( f ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9781003069638/440efdcf-c2ed-414a-bdad-7c98e059177f/content/eq112.tif"/> and S I B ( f ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9781003069638/440efdcf-c2ed-414a-bdad-7c98e059177f/content/eq113.tif"/> ) and an indirect highly sensitive technique based on noise figure characterization. The S I C ( f ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9781003069638/440efdcf-c2ed-414a-bdad-7c98e059177f/content/eq114.tif"/> and S I B ( f ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9781003069638/440efdcf-c2ed-414a-bdad-7c98e059177f/content/eq115.tif"/> follows a 1/f dependence at low frequencies, for moderate bias conditions. A Lorentz component is found in the spectra. The base resistances are obtained by approximating them to the correlation resistances and range from 17Ω to 63Ω. The intrinsic noise sources are studied using a simple model employing two internal, uncorrected noise sources. These sources are similar to the S I C ( f ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9781003069638/440efdcf-c2ed-414a-bdad-7c98e059177f/content/eq116.tif"/> and S I B ( f ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9781003069638/440efdcf-c2ed-414a-bdad-7c98e059177f/content/eq117.tif"/> at moderate bias conditions. However, the intrinsic collector noise differs from S I C ( f ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9781003069638/440efdcf-c2ed-414a-bdad-7c98e059177f/content/eq118.tif"/> at low bias conditions.
