Contour plots of the pairs x and dϕ that would allow to reach a desired compensated rejection ratio, M_Uc. Every contour represents a different value of analog rejection, M_A, of the receiver with IF hybrid. The innermost curve (thick red) represents the situation when no IF hybrid is present. Panel a: M_Uc = 30 dB and panel b: M_Uc = 40 dB. The higher the desired compensation, the closer and need to be.