A Fourier Transform Based Technique for Reduction of Standing Waves in Millimeter Wave Spectral Line Measurements

A standing wave due to reflections from the calibration loads is regularly detected in millimeter-wave spectral line measurements using load switching techniques. A Fourier transform based technique for reduction of the standing wave is presented in this paper. This new method has been demonstrated in the case of an ozone radiometer at 110.836 GHz. The results compare favorably with those obtained with mechanical phase shifter reduction techniques.