In summary, Analog’s In-phase quadrature (I/Q) mixers and image reject mixers (IRM) offer a robust frequency mixing solution for applications that require high image rejection or sideband suppression. These mixers can be used as an up-converter or down-converter. I/Q or IRM mixers use two double-balanced mixers with a 90° hybrid. The inherent architecture of I/Q mixers eliminates the resulting product due to image frequency during down-conversion and allows the selection of desired sideband during up-conversion. An image reject notch filter can be used at the RF input port to reduce the extra noise and spurious from the USB. However, when the RF frequency and the LO frequency are very close together (low frequency IF), it becomes difficult to realize a filter that suppresses the USB while having no effect on the desired sideband. The image reject topology described in these slides can be used in place of an image reject filter. The spacing of the LO to RF can be very close in an image reject architecture with no adverse effect on the desired sideband.