5.2.2 Double side band system

In that case the signals coming from the upper and lower side bands have similar attenuation in the RF part and similar conversion loss in the mixers. They will have similar amplitudes in the correlator output. The result for the cosine correlator is:

$$V = \ensuremath{A_\mathrm{\scriptscriptstyle U}} e^{i[\ensure... ...ptstyle 2}}\ensuremath{\tau_\mathrm{\scriptscriptstyle G}} )]}$$ (5.12)

Assuming the same visibility in both sidebands:

$$V = \ensuremath{A_\mathrm{\scriptscriptstyle }}\cos{(\ensurem... ...iptstyle 2}}\ensuremath{\tau_\mathrm{\scriptscriptstyle G}} )}$$ (5.13)

If the delays are tracked, and the LO phases rotated as above, the exponential term is 1 and only the real part of the visibility is measured. Some trick is thus needed to separate the signal from the side bands.