Ma, Weiming, Wang, Zhaokai, Gao, Yang, Li, Lei, Du, Guanxiang, and Guo, Haizhong
International Journal of RF & Microwave Computer-Aided Engineering. Dec2022, Vol. 32 Issue 12, p1-10. 10p.
BANDPASS filters, WAVEGUIDE filters, MAGNETIC sensors, MAGNETIC fields, DIAMONDS, and MICROWAVES
In diamond nitrogen‐vacancy (NV) magnetic field sensors, microwave delivery and irradiation with efficient, uniform, and wide dynamic range are necessary to achieve more accurate measurement and higher sensitivity. Here, we report on the development of a triple‐mode broadband waveguide bandpass filter (BPF), which uses a high‐Q metallic cavity to transfer the microwave and excite the diamond NV spin ensembles. This BPF provides a more efficient, low‐loss, uniform, and broadband microwave signal, as well as a closed space for the NV‐quantum sensor. The developed BPF exhibits a large fractional bandwidth (FBW) of 34.8% with a center frequency of 2.87 GHz, and this leads to improve the measurable static magnetic field range up to 5.36 × 10−2 T. Experimental results show that the sensitivity is improved to 14.67 μT/Hz1/2 compared to the patch antenna of 188.49 μT/Hz1/2, that is usually used in the conventional diamond NV‐based quantum sensors. [ABSTRACT FROM AUTHOR]
Chinese Physics B. Sep2022, Vol. 31 Issue 9, p1-6. 6p.
AMPLITUDE modulation detectors, PHASE detectors, RYDBERG states, and RADIO frequency
Recently, a Rydberg atom-based mixer was developed to measure the phase of a radio frequency (RF) field. The phase of the signal RF (SIG RF) field is down-converted directly to the phase of a beat signal created by the presence of a local RF (LO RF) field. In this study, we propose that the Rydberg atom-based mixer can be converted to an all-optical phase detector by amplitude modulation (AM) of the LO RF field; that is, the phase of the SIG RF field is related to both the amplitude and phase of the beat signal. When the AM frequency of the LO RF field is the same as the frequency of the beat signal, the beat signal will further interfere with the AM of the LO RF field inside the atom, and then the amplitude of the beat signal is related to the phase of the SIG RF field. The amplitude of the beat signal and the phase of the SIG RF field show a linear relationship within the range of 0 to Ď€ /2 when the phase of the AM is set with a difference Ď€ /4 from the phase of the LO RF field. The minimum phase resolution can be as small as 0.6Â° by optimizing the experimental conditions according to a simple theoretical model. This study will expand and contribute to the development of RF measurement devices based on Rydberg atoms. [ABSTRACT FROM AUTHOR]