The NQR RF decoupler construction based on transformer

This paper will present some experiments with improving one of crucial parts of nuclear quadrupolar resonance (NQR) spectrometer, the RF decoupler. This part decouples the high power rf excitation signal from receiver port of low detected signal preamplifier. In the position of decoupler usually some LC filters and back-to-back diodes are used. We have tested rf impedance transformers of different types in rf decoupler construction, suitable for our experimental NQR spectrometer with the working frequency range from 0.5 to approximately 50 MHz. Obtained results show very good applicability of this transformers in NQR circuitry. The measured impedance and transition times between on and off state of the proposed decoupler will be discussed in this paper.