Millimeter-Wave Low Spurious Quadruple Harmonic Image Rejection Mixer with 90-degree LO Power Divider

This paper describes a millimeter-wave low spurious quadruple harmonic image rejection mixer (IRM). The even harmonic mixer with the anti-parallel diode pair (APDP) cancels the even harmonics of the input signal and the LO wave. But if we use the higher order harmonic mixer as an up-conversion mixer, there are many odd-order spurious signals that locate nearby a desired RF signal. In order to obtain a low spurious performance of the quadruple harmonic IRM, it employs the 90-degree divider for the LO wave in addition to the RF signal and the IF signal. In the fabricated 60 GHz band IRM MMIC, the 30 dB suppression of the 5th order LO harmonics (5LO) can be achieved by the proposed IRM configuration compared with the conventional one. Realization of the low spurious harmonic mixer is useful for the low cost millimeter-wave commercial production.