Advantages of digital phase-sensitive detection for upgrading an obsolete CW EPR spectrometer

摘要: The replacement of the commonly used analog phase-sensitive detection (PSD) by digital PSD for demodulation electron paramagnetic resonance (EPR) signals is suggested upgrading an out-of-date EPR spectrometer. Connection microwave bridge output to a fast analog-digital converter (ADC) eliminates some spectrometer’s components: electronics responsible PSD, ADC sampling demodulated signals, and computer, as well usage settings. spectrometer reduced magnet, bridge, personal computer containing board. digitized set magnetic field positions form two-dimensional array which stored in computer. Demodulation filtering are done numerically produce conventional spectrum. In comparison with this numerical approach does not eliminate out-of-phase component signal at higher harmonics modulation frequency. details modernizing Bruker ER200E SRC discussed demonstrate these other advantages demodulation.