Note: innovative demodulation scheme for coherent detectors in cosmic microwave background experiments.
Rev Sci Instrum
; 83(5): 056104, 2012 May.
Article
en En
| MEDLINE
| ID: mdl-22667668
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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Colección:
01-internacional
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MEDLINE
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En
Revista:
Rev Sci Instrum
Año:
2012
Tipo del documento:
Article
País de afiliación:
Japón