This thesis proposes a novel architecture for high frequency synthesizer design focusing mainly on the 60 GHz frequency range. It consists of a PLL cascaded to an ILO. In order to generate narrow pulses and to relax the multiplication ration of the ILO, a DLL with a pulse generator is used. Passive delay line stacked on top of LC VCO is used for power efficiency and replica-biasing technique of frequency tracking is used for increasing the locking range of ILO. The synthesizer operates at 50 GHz with a phase noise of -98, -117 and -128 dBc/Hz at 1 MHz, 10 MHz and 40 MHz respectively. The total power consumed by the frequency synthesizer from 1.2 V supply is 57 mW. To have channel selection capability, fractional PLL may be used. A novel fractional PLL architecture is also proposed which de-couples the residual jitter from the PLL bandwidth.