The design and analysis of a fully differential LC tank based voltage controlled oscillator is discussed in this paper. The oscillator is negative gm based and the CMOS cross-coupled pair used in the design provides the negative resistance to sustain the oscillations. The tuning range is about 43% with 2.4GHz as the center frequency. The phase noise at an offset of 1MHz is 135.6dBc/Hz. The design consumes 6.17mW power from a supply voltage of 3.3V. The supply sensitivity of the design is 2.5% for ±5% variation in the supply voltage. © 2017 IEEE.