Sideband ratio G_usb (see Sect. 2) as a function of local oscillator frequency for all 7 HIFI bands. The red lines show the result of our fit with the 1σ confidence region shown as a pink envelope. The black lines represent the finally adopted values in the calibration tables. The dashed lines indicate the 1σ uncertainty. Each panel contains 2 sub-panels; the upper panel shows the H polarisation and the lower panel indicates V polarisation. In those panels we no longer distinguish between the a and b parts of the mixer band.