A Tail-Injected Divide-by-4 SiGe HBT Injection Locked Frequency Divider

This letter presents a silicon-germanium (SiGe) heterojunction bipolar transistor (HBT) divide-by-4 injection locked frequency divider (ILFD). The ILFD is based on a single-stage voltage-controlled oscillator with active-inductor, and was fabricated in the 0.35 mu m SiGe 3P3M BiCMOS technology. The divide-by-4 function is performed by injecting a signal to the base of the tail HBT. Measurement results show that when the supply voltage V_DD is 3.1 V and the tuning voltage is tuned from 2.0 to 2.8 V, the divider free-running oscillation frequency is tunable from 2.12 to 2.76 GHz, and at the incident power of 0 dBm the operation range is about 1.15 GHz, from the incident frequency 8.55 to 9.7 GHz. The die area is 0.65 times 0.435 mm².