A passive implementation of an image reject mixer (IRM), capable of operating at very high frequency, is manufactured in a variety of silicon processes. The IRM comprises a quad MOS multiplier and a lumped-element hybrid, resulting in a passive IRM, operative at radio frequencies (RF) of tens of GHz with an intermediate frequency (IF) of several GHz. The RF+ and RF− signals are provided to two quad MOS multipliers. A local oscillator signal (LO) is used to provide LO+ and LO− signals to one of the multipliers and by providing the LO to a phase shifter, generated are a ninety degree shifted LO+ and LO− signals provided to the other multiplier. Providing the hybrids with the outputs of both multipliers and selecting an appropriate IF signal from each of the hybrids ensures the proper operation of the passive IRM.