The chart on this slide shows low side injection, with RF/LO = 1.1. The black color represents the fundamental LO and the LO harmonics out to 5x. The cyan color represent the RF signal and the harmonics out to 5x. Blue represents the IF out fundamental. Green represents the 2x2, red the 3x3, and the magenta represents the 3x2 and the 4x3 mixing components. Note that the 2x2 and the 3x3 spurs are the same as the 2nd and 3rd harmonics of the IF.