Microwave noise of Si/Si/sub 0.6/Ge/sub 0.4/ heterojunction bipolar transistors

The microwave noise of Si/SiGe HBTs was characterized wid modeled using a highfrequency T-ecluivillent noise circuit model. A 6 finger 2x15 pn2 HBT showed a minimum noise riigu1.e of 2.2GdB with an associated gain of 12.7d8, measured at 8 GHz under Ic=14mA and Vc,,=3V bias condition. Bias, frequency and H3T geometry dependent noise measurements were also perrormcd. It was found that the 6 fingcr 2x15 binz HBT has thc bcst noisc performance among the characterized devices. Moreover, it was rcvcalcd [hilt minimum noise figure reaches a minimum at R medium collcctor currcnt. Finally, a s implc all physical h igh-frequenc y T-equivalent noise model was extracted from the measured Sparameters aiid noise data and was used for the study of noise dependence on different HBT equivalent circuit parameters.