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This paper realized a charge pump phase locked loop (CPPLL) frequency source circuit based on 0.15 μm Win GaAs pHEMT process. In this paper, an improved fully differential edge-triggered frequency discriminator (PFD) and an improved differential structure charge pump (CP) are proposed respectively. In addition, a low noise voltage-controlled oscillator (VCO) and a static 64:1 frequency divider is realized. Finally, the phase locked loop (PLL) is realized by cascading each module. Measurement results show that the output signal frequency of the proposed CPPLL is 3.584 GHz-4.021 GHz, the phase noise at the frequency offset of 1 MHz is -117.82 dBc/Hz, and the maximum output power is 4.34 dBm. The chip area is 2701 μm × 3381 μm, and the power consumption is 181 mw.
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http://dx.doi.org/10.3390/s22020504 | DOI Listing |
Folia Microbiol (Praha)
September 2025
Department of Biomedical Science and Technology, The School of Biological Sciences, Ramakrishna Mission Vivekananda Educational and Research Institute, Howrah, West Bengal, 711202, India.
Colistin resistance represents a mounting global health concern, particularly alarming in the face of multidrug-resistant (MDR) and extensively drug-resistant (XDR) bacterial infections. As a polymyxin-class antibiotic, colistin has long served as a critical last-line defence against severe Gram-negative infections caused by pathogens such as Pseudomonas aeruginosa, Acinetobacter baumannii, and Klebsiella pneumoniae. However, its increasing and, at times, indiscriminate use has driven the emergence of resistant strains, thereby compromising its clinical utility.
View Article and Find Full Text PDFSynchrotron Radiat News
May 2025
SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA.
Time-resolved x-ray spectroscopy has become a powerful approach for probing the ultrafast dynamics of photoexcited systems in solution, offering a window into the structural and electronic transformations that govern function for instance in catalytic or biological systems. At SLAC, the colocation of the Stanford Synchrotron Radiation Lightsource (SSRL) and the Linac Coherent Light Source (LCLS) enables a uniquely synergistic platform for ultrafast studies. Together, these facilities span a broad temporal range, from fs to ns, allowing multiscale investigations of excited-state dynamics using complementary techniques such as x-ray absorption, emission, and scattering.
View Article and Find Full Text PDFPhys Rev Lett
August 2025
Northeastern University, Department of Physics, Boston, Massachusetts 02115, USA.
The dynamical phase transition of a system with two coexisting competing order parameters is studied using the time-dependent-Ginzburg-Landau framework. The dynamics are induced by parameters capturing the physics of driving the system with an ultrafast laser pulse. A remarkable enhancement of the order parameter with a smaller mean-field value following the pump and the emergence of an induced metastable state is investigated through analytical and numerical studies.
View Article and Find Full Text PDFJ Chem Phys
August 2025
Department of Chemistry and Biochemistry, Institute for Physical Science and Technology, University of Maryland, College Park, Maryland 20742, USA.
We formulate a semiclassical theory for electron transport in open quantum systems with electron-phonon interactions adequate for situations when the system's phonon dynamics is comparable with the electron transport timescale. Starting from the Keldysh non-equilibrium Green's function formalism, we obtain equations of motion for the retarded and lesser electronic Green's functions, including contributions due to the phonon dynamics up to second order in the electron-phonon coupling strength. The resulting equations assume that the system's phonons follow classical time-local dynamics with delta-correlated noise.
View Article and Find Full Text PDFNat Chem
August 2025
Institut für Physik, Carl von Ossietzky Universität, Oldenburg, Germany.
Quadrupolar dyes, such as acceptor-donor-acceptor molecules, are highly relevant for applications in nonlinear optics and photovoltaics. They are also versatile models for exploring photoinduced charge-transfer dynamics. The interplay between electronic and vibronic couplings in these molecules may break excited-state symmetry, resulting in intramolecular charge separation and pronounced solvatochromism.
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