Innovative Demodulation Scheme for Coherent Detectors in CMB Experiments
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.
Keywords
Cite
@article{arxiv.1203.2407,
title = {Innovative Demodulation Scheme for Coherent Detectors in CMB Experiments},
author = {K. Ishidoshiro and Y. Chinone and M. Hasegawa and M. Hazumi and M. Nagai and O. Tajima},
journal= {arXiv preprint arXiv:1203.2407},
year = {2012}
}
Comments
3 pages, 4 figures