This letter presents a wide‐band 2:1 injection‐locked frequency divider (ILFD) in the 0.18 μm BiCMOS process with circuit model of class‐AB. The ILFD uses an 8‐shaped inductor in shunt with parasitic capacitors as the resonator, and it also employs two capacitive cross‐coupled pairs to generate negative resistance for oscillation. The gate biases of capacitive cross‐coupled pairs are fully utilized to tune the free‐running ILFD oscillation frequency. At the power consumption of 2.064 mW and the input power of 0 dBm, the locking range frequency is 71.3% (from 3.7 to 7.8 GHz) and the figure of merit (FOM) is 34.54. As compared to other ILFDs using octagonal inductors, this ILFD has low EM radiation level and less sensitivity to received EM noise.

This letter presents a lower phase noise voltage-controlled oscillator (VCO) uses two differential amplifiers in crosscoupled feedback and is named as a buffer-reused VCO in the TSMC standard 0.18 μm SiGe BiCMOS processes. The die area is 1.1 × 1.2 mm 2 . The first amplifier uses HBT stacking on nMOSFET and the second amplifier uses nMOS amplifier. Its power consumption of 2.65 mW with output buffer current, the phase noise is −128.81 dBc/Hz at 1 MHz offset frequency from the center frequency 4.19 GHz. The figure of merit (FOM) is −194.08 dBc/Hz.