Abstract: A compact integrative millimeter-wave hybrid integrated local oscillator-mixer component and its design method are presented in this paper. This component consists of a mechanical tuning finline Gunn oscillator and a balanced mixer using a simple finline-microstrip magic-T structure. The measured values of the designed and fabricated component at the Ka band have been obtained:with LO at 35 GHz, the conversion loss of 4.7 to 9.5 dB has been achieved with RF varied from 26.5 to 40 GHz; and with IF at 100 MHz, the conversion loss of 4.9 to 6.2 dB has been achieved when the RF is changed with LO which is varied from 33 to 37 GHz.