Abstract: The present invention relates to an up conversion RF mixer having first differential transistor pair comprising first and second transistors and a second differential transistor pair having third and fourth transistors. The emitters of the first and second transistors are connected to the drain of a fifth transistor and the emitters of the third and fourth transistors are connected to the drain of a sixth transistor. The sources of the fifth and sixth transistors are connected to drains of seventh and eighth transistors, respectively. A local oscillator signal is connected to the bases of the first and second transistors and to the bases of the third and fourth transistors. A first intermediate frequency signal is connected to the gate of the fifth transistor and the gate of the eighth transistor. A second intermediate frequency signal which is the inverse of the first intermediate frequency signal is connected to the gates of the sixth and seventh transistors.