Development of high f/sub MAX/ SiGe HBT with air-bridge

In this paper. a SiGe HBT was described, which was based on a unique process technology. To characterize the SiGe HBT, HP85 10C network analyzer, HP83650A synthetic signal sources, HP8517b S parameter measuring systems etc. have been used for measuring radiofrequency performance of SiGe HBT. The measurements showed satisfactory results. The SiGe HBT cutoff frequency f/sub T/ is 108 GHz, and the maximum oscillation frequency is 157 GHz.