ABSTRACT
Because of Si-based processing, the low-frequency noise in SiGe HBTs is comparable to that in Si
BJTs, which is typically much better (lower) than in III-V HBTs [1-3]. Of particular importance is
the 1/f noise or flicker noise, which dominates at low frequency, and can be upconverted to phase noise
in RF oscillators through nonlinear I-V and C-V relationships inherent to the transistor. This results in
noise sidebands on the carrier frequency, which fundamentally limits spectral purity. Low-frequency noise
is also very important for wireless receivers utilizing zero or very low intermediate frequency (IF)
architectures.