All-digital PLLs promise flexible and precise FMCW radar signal generation for 77GHz radar applications. Such PLLs require digitally-controlled oscillators (DCO) with wide frequency tuning range (FTR) and high resolution to address a range of applications and low phase noise requirements. In this work, novel resonator structures with fine capacitance/inductance switching are embedded in a wide FTR common-source Colpitts DCO to achieve <;1MHz DCO frequency resolution at 78GHz. The proposed structures also reduce dependence on switch-position for frequency step size, simplifying calibration. The DCO implemented in 65nm CMOS occupies 0.1mm2 and consumes 15.6mW to achieve 74.6GHz-83.6GHz FTR (11.4%) with 370kHz resolution, phase noise of -115dBc/Hz at 10MHz offset at 80GHz and state-of-the-art mm-wave DCO FoM-T of -182dBc/Hz.