A 79 GHz dynamic frequency divider in SiGe bipolar technology

Conventional static frequency dividers use master-slave flipflops to achieve frequency division. They allow broadband operation down to DC as long as the slew rate of the input signal is high enough. Their upper frequency, however, is Limited by the gate delay /spl tau//sub D/ to a value of approximately 1/(2 /spl tau//sub D/). Significantly higher operating frequencies can be achieved by dynamic frequency dividers. The limited bandwidth of dynamic dividers is a drawback but poses no problem in many applications which require divider operation only in a specific frequency range. Dynamic dividers manufactured in III-V-technologies and, recently, in SiGe technology achieve maximum operating frequencies of 60 GHz to 75 GHz. However, most of these circuits operate over relatively narrow bandwidths of less than one octave. This regenerative frequency divider exploits the high-speed potential of SiGe technologies to combine high maximum frequency with operation over wide frequency range.