Deployment of a transportable Yb optical lattice clock.

We report on the first deployment of a ytterbium (Yb) transportable optical lattice clock (TOLC), commercially shipping the clock 3000 km from Boulder, Colorado, to Washington DC. The system, composed of a rigidly mounted optical reference cavity, an atomic physics package, and an optical frequency comb, fully realizes an independent frequency standard for comparisons in the optical and microwave domains. The shipped Yb TOLC was fully operational within 2 days of arrival, enabling frequency comparison with a rubidium (Rb) fountain at the United States Naval Observatory (USNO).

Ultra-Low Phase Noise Frequency Division With Array of Direct Digital Synthesizers.

In this article, we present a four-channel direct digital synthesis (DDS) design that operates with a common clock ranging from 500 MHz to 24 GHz and generates output frequencies up to 1.75 GHz. A key feature of this board is its custom field-programmable gate array (FPGA)-based synchronization method, which ensures alignment accuracy of 170 ps between the channels, enabling precise frequency and phase relationship settings.

Residual LSTM-based short duration forecasting of polarization current for effective assessment of transformers insulation.

The empirical application of polarization and depolarization current (PDC) measurement of transformers facilitates the extraction of critical insulation-sensitive parameters. This technique, rooted in time-domain dielectric response analysis, forms the bedrock for parameterization and insulation modeling. However, the inherently time-consuming nature of polarization current measurements renders them susceptible to data corruption.

Ultralow PM and AM Noise Generation With an Ensemble of Phase-Coherent Oscillators.

This article investigates the performance of an array of multiple phase-coherent power-combined oscillators (PPOs) in terms of phase modulation (PM) noise and amplitude modulation (AM) noise. The array consists of six individual oscillator modules that generate three distinct frequencies: 10, 100 MHz, and 1 GHz. By meticulously aligning the phases, we observed a notable improvement of approximately 7.