Related papers: Phase synchronisation system receiver module for t…
We present a stabilized microwave-frequency transfer technique that is based on optical phase-sensing and optical phase-actuation. This technique shares several attributes with optical-frequency transfer and therefore exhibits several…
The next generation Very Large Array project (ngVLA) would represent a major step forward in sensitivity and resolution for radio astronomy, with ability to achieve 2 milli-arcsec resolution at 100 GHz (assuming a maximum baseline of 300…
The Square Kilometre Array (SKA) project is an international effort to build the world s largest radio telescope, enabling science with unprecedented detail and survey speed. The project spans over a decade and is now at a mature stage,…
High-precision optical pulse trains distribution via fibre links has made huge impacts in many fields. In most published works, the accuracies are still fundamentally limited by some unavoidable noises, such as thermal and shot noise from…
The design and development process for the Square Kilometre Array (SKA) radio telescope, the Low Frequency Aperture Array component, was progressed during the SKA pre-construction phase by an international consortium, with the goal of…
In conventional radar, the transmission of the same waveform is repeated after a predefined interval of time called pulse-repetition-interval (PRI). This technique helps to estimate the range and Doppler shift of targets and suppress…
This paper presents a framework to compute the receiver noise temperature (Trcv) of two low-frequency radio telescopes, the Murchison Widefield Array (MWA) and the Engineering Development Array (EDA). The MWA was selected because it is the…
For the submillimeter band observations, we have been routinely adopting the calibration cycle time of 20-30 minutes, which is the same as any typical centimeter and millimeter band observations. This cycle time, largely corrects only the…
We describe and experimentally evaluate a stabilized radio-frequency transfer technique that employs optical phase sensing and optical phase actuation. This technique can be achieved by modifying existing stabilized optical frequency…
The volume of mobile data traffic has been driven to an unprecedented high level due to the proliferation of smartphones/mobile devices that support a wide range of broadband applications and services, requiring a next generation mobile…
Multiple-input multiple-output (MIMO) systems using Rydberg atomic (RA) receivers face significant scalability challenges in signal detection due to their nonlinear signal models. This letter proposes phase-rotated symbol spreading (PRSS),…
Radio interferometers are phased arrays producing high-resolution images from the covariance matrix of measurements. Calibration of such instruments is necessary and is a critical task. This is how the estimation of instrumental errors is…
We review the conventional phase-locking technique in the long-term stabilization of the mode-locked fiber laser and investigate the phase noise limitation of the conventional technique. To break the limitation, we propose an improved…
A clock synchronizing circuit for repeaterless low swing interconnects is presented in this paper. The circuit uses a delay locked loop (DLL) to generate multiple phases of the clock, of which the one closest to the center of the eye is…
Calibration is crucial for ensuring the performance of phased array since amplitude-phase imbalance between elements results in significant performance degradation. While amplitude-only calibration methods offer advantages when phase…
As the Square Kilometre Array (SKA) approaches operational status, its complex digital architecture introduces new instrumental challenges. To explore relevant observational and data processing strategies, we have upgraded the 21CMA…
Entanglement generation between remote qubit systems is the central tasks for quantum communication. Future quantum networks will have to be compatible with low-loss telecom bands and operate with large separation between qubit nodes.…
In this proceeding, we summarize the key science goals and reference design for a next-generation Very Large Array (ngVLA) that is envisaged to operate in the 2030s. The ngVLA is an interferometric array with more than 10 times the…
Radio astronomy observations in the coming decade will require new levels of sensitivity while mapping large regions of space with much greater efficiency than is achieved with current telescopes. This requires new instrumentation with the…
Precise measurements of the frequency and phase of an electrical or optical signal play a key role in various branches of science and engineering. Tracking changing laser frequencies is especially demanding when the lasers themselves are…