Modeling Of Ge—Si Heterojunction Bipolar Transistors For Use In Silicon Monolithic Millimeter-Wave Integrated Circuits

Previous work on high-resistivity silicon suggests that microstrip line dielectric losses cease to be significant above 30 GHz. Silicon—Germanium heterojunction bipolar transistors now provide a well-behaved three-terminal device capable of operating at microwave frequencies, making the fabrication of silicon monolithic millimeter-wave integrated circuits a genuine possibility. The trade-offs available to operate this device at millimeter-wave frequencies are discussed, and one-dimensional calculations along with two-dimensional simulations of transistor performance are presented.