A system for measuring the amplitude and phase of three components of the e
lectric field vector at 2450 MHz is described. It uses three optically modu
lated phototransistors which disturb only weakly the electric field distrib
ution.
The authors also present two guide setups, for calibrating the sensor and f
or evaluating its performance. The sensor can either be moved with a slidin
g matched load inside the waveguide, or be positioned in the waveguide in f
ront of a movable short circuit. The two procedures are compared.