Abstract: The development for smart millimeter wave jumping frequency synthesizer is suggested in this paper. To meet the need of miniaturization, the method of phase locked in microwave band and then multiplying into millimeter wave band is applied, and the super-small, ordinary 10 MHz crystal oscillator is chosen in the system. The volume of the synthesizer is in 150 cm3. The testing results show that phase noise is better than-65dBc/Hz@10kHz and output power is over 10 dBm in 29~31 GHz output frequency and 20 MHz step frequency. The millimeter synthesizer can be used in the Ka-band receiver as local oscillator or the transmitter as standard source.