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arXiv · 1203.2407

Innovative Demodulation Scheme for Coherent Detectors in CMB Experiments

K. Ishidoshiro·Y. Chinone·M. Hasegawa·M. Hazumi·M. Nagai·O. Tajima
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Abstract

We propose an innovative demodulation scheme for coherent detectors used in cosmic microwave background polarization experiments. Removal of non-white noise, e.g., narrow-band noise, in detectors is one of the key requirements for the experiments. A combination of modulation and demodulation is used to extract polarization signals as well as to suppress such noise. Traditional demodulation, which is based on the two- point numerical differentiation, works as a first-order high pass filter for the noise. The proposed demodulation is based on the three-point numerical differentiation. It works as a second-order high pass filter. By using a real detector, we confirmed significant improvements of suppression power for the narrow-band noise. We also found improvement of the noise floor.

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K. Ishidoshiro, Y. Chinone, M. Hasegawa, M. Hazumi, M. Nagai, O. Tajima. 2012-05-21. Innovative Demodulation Scheme for Coherent Detectors in CMB Experiments. https://doi.org/10.1063/1.4719922

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