A 0.3-THz SiGe-Based Sub-Harmonic Injection Locked Oscillator

This letter presents a transformer based 0.3-THz injection-locked differential Colpitts oscillator fabricated in 130nm SiGe BiCMOS process. The circuit converts the injected signal at 96-110 GHz to the output signal at 288-330 GHz, achieving more than 13% locking range with a 5 dBm injection power. The circuit employs Marchand baluns for signal injection, obviating the requirement for active elements for injection locking. The free-running frequency and output power of the oscillator are 293 GHz and -2.3dBm. In the locking range, the oscillator can achieve a phase noise of-124 dBc/Hz at 10-MHz offset and delivers a peak output power of -1.1 dBm. The core of the chip occupies a die area of 0.14 mm²