QUBiC4G: a f/sub T//f/sub max/ = 70/100 GHz 0.25 μm low power SiGe-BiCMOS production technology with high quality passives for 12.5 Gb/s optical networking and emerging wireless applications up to 20 GHz

10-40GHz design in SiGe-BiCMOS and Si-CMOS linking technology and circuits to maximize performance

“…Firstly, it can be seen that f cross is relatively independent of the bias current for an order of magnitude in bias current variations. This can be explained from equation (4). For bias conditions below the current density for peak-f T , the increase in f T for increased bias current is compensated by a reduction in f V .…”

“…A differential pair amplifier biased at peak-f T may not provide the maximum bandwidth in this process. The transition from [3] to [4] was driven by an increase in peak-f T , made possible through the introduction of a SiGe layer. The higher peak-f T is obtained at an increased current density.…”

“…Despite the increase in f T and f max from [3] to [4], a relatively poor improvement in broadband circuit bandwidths was found. Reversely, the transition from [4] to [5] resulted in a significant circuit performance increase. In Section IV, some circuit examples and their relation to device metrics will be described.…”

“…In Section III, the evolution of these metrics across 3 generations of a BiCMOS process is reviewed. While the transition from [3] to [4] was driven by metrics f T and f max , the transition from [4] to [5] was driven by f T , f A and f cross . Despite the increase in f T and f max from [3] to [4], a relatively poor improvement in broadband circuit bandwidths was found.…”

“…While the transition from [3] to [4] was driven by metrics f T and f max , the transition from [4] to [5] was driven by f T , f A and f cross . Despite the increase in f T and f max from [3] to [4], a relatively poor improvement in broadband circuit bandwidths was found. Reversely, the transition from [4] to [5] resulted in a significant circuit performance increase.…”