Improving the bandwidth of Rydberg atom-based receivers is an ongoing challenge owing to the long-lived Rydberg state lifetimes that limit the refresh rate of ground state atoms.In particular, the LO-based Rydberg mixer approach allows for bandwidths into the few-MHz range.Here we use heterodyne detection of the Rydberg atom receiver probe laser to separate the negative and positive sidebands that originate from distinct six wave mixing processes in order to investigate their individual bandwidths.We experimentally confirm the prediction that the negative sideband exhibits a higher bandwidth than the positive sideband.We further explore the effect of coupling and probe laser Rabi frequency on the bandwidth, which we find to be in good agreement with our model. We achieved a maximum experimental (and theoretical) bandwidth of about 11 (11)~MHz and 3.5 (5)~MHz for the negative and positive sidebands, respectively, from the -3dB roll-off point for optimized field parameters.This work provides insight into the bandwidth-limiting features of Rydberg atom receivers and points the way towards further optimization of their response.

Rydberg atom-based receivers of modulated radio frequency (RF) fields are promising systems for measurements. These systems are self-calibrating, widely tunable, nearly transparent to RF fields, and can be electrically small. However, the instantaneous bandwidth of current Rydberg atom receivers is typically less than 1 MHz. Using two-photon electromagnetically induced transparency (EIT) to observe the 56D5/2 Rydberg state in cesium, we measure modulation sidebands on each tooth in a probe optical frequency comb that spans the D2 F=4-F'=5 transition resulting from transmission modulation of the probe beam. This transmission modulation occurs from changes in susceptibility of the room temperature cesium vapor as two RF fields impinge on the atoms. A strong RF local oscillator is resonant with the 56D-57P state and mixes with a weak RF signal field detuned from the RF LO by an intermediate frequency. Using a self-heterodyned electro-optic comb setup, we separate positive and negative sideband amplitudes and compare to an equivalent comb-free system. These data report EIT measurement with the comb system, local spectra around two comb teeth - one within and one outside the EIT line, and normalized minimum detectable RF signal field as a function of RF intermediate frequency used to evaluate the instantaneous bandwidth of the single frequency, positive sideband, and negative sideband datasets.

On-resonance Rydberg atom-based radio-frequency (RF) electric field sensing methods remain limited by the narrow frequency signal detection bands available by resonant transitions. The use ofan additional RF tuner field to dress or shift a target Rydberg state can be used to return a detuned signal field to resonance and thus dramatically extend the frequency range available for resonantsensing. Here we compare three distinct tuning schemes based on adjacent Rydberg transitions, which are shown to have distinct tuning characteristics and can be tuned with mechanisms based onthe tuning field frequency or field strength. We further show that a two-photon Raman feature can be used as an effective tuning mechanism separate from conventional Autler-Townes splitting. Wecompare our tuning schemes to AC Stark effect-based broadband RF field sensing and show that although the sensitivity is diminished as we tune away from a resonant state, it nevertheless can beused in configurations where there is a low density of Rydberg states, which would result in a weak AC Stark effect.

Deep subwavelength RF imaging with atomic Rydberg sensors has overcome fundamental limitations of traditionalantennas and enabled ultra-wideband detection of omni-directional time varying fields all in a compactform factor. However, in most applications, Rydberg sensors require the use of a secondary strong RF referencefield to serve as a phase reference. Here, we demonstrate a new type of Rydberg sensor for Angle-of-Arrival(AoA) sensing which utilizes subwavelength imaging of standing wave fields. By placing a metallic plate withinthe Rydberg cell, we can determine the AoA independent of the strength of incoming RF field and without requiringa secondary strong RF phase reference field. We perform precision AoA measurements with a roboticantenna positioning system for 4.2, 5.0, and 5.7 GHz signals and demonstrate a 1.7◦ polar angular resolutionfrom 0◦ to 60◦ AoA and 4.1◦ over all possible angles.

Although Rydberg atom-based electric field sensing provides key advantages over traditional antenna-based detection, it remains limited by the need for a local oscillator (LO) for low-field and phase resolved detection. In this work, we demonstrate the general applicability of closed-loop quantum interferometric schemes for Rydberg field sensing, which eliminate the need for an LO. We reveal that the quantum-interferometrically defined phase and frequency of our scheme provides an internal reference that enables LO-free full 360 degree-resolved phase sensitivity. This internal reference can further be used analogously to a traditional LO for atom-based down-mixing to an intermediate frequency for lock-in-based phase detection, which we demonstrate by demodulating a four phase-state signal broadcast on the atoms.

Data presented is part of the journal manuscript "Optically Distributing Remote Two-node Microwave Entanglement using Doubly Parametric Quantum Transducers." Data includes graphical plots generated from numerical models and computations for various network topologies which illustrate their thresholds for achieving quantum information transfer.

The Nimbus High Resolution Infrared Radiometer Digital Swath Data L1, HDF data set (NmHRIR1H) consists of High Resolution Infrared Radiometer (HRIR) brightness temperatures obtained by the Nimbus 1, Nimbus 2, and Nimbus 3 satellites during 1964, 1966, and 1969. A correction has been applied to minimize seemingly random alignment errors that caused clouds edges and land features to appear jagged in the original 1960s data.

This data was used for main results for the paper entitled "Coherent Optical Clock Down-Conversion for Microwave Frequencies with 10-18 Instability". We could calculate relative phase fluctuation and Allan deviation for both Yb optical clocks and 10 GHz microwaves. Uncertainty of our down-conversion system was also calculated from this.

After a five-year renovation of the National Institute of Standards and Technology (NIST) Boulder, CO, antenna measurement facility, the Antenna On-Axis Gain and Polarization Measurements Service SKU63100S was reinstated with the Bureau International des Poids et Mesures (BIPM). In addition to an overhaul of the antenna facility, the process of reinstatement involved a comprehensive measurement campaign of multiple international check-standard antennas over multiple frequency bands spanning 8 GHz to 110 GHz. Through the measurement campaign, equivalency with 16 National Metrology Institutes (NMIs) and continuity to several decades of antenna gain values was demonstrated. The renovation process, which included implementing new robotic antenna measurement systems, control software, and data processing tools is discussed. Equivalency results and uncertainties are presented and compared to check standard historical values. Data sets included here are for figures 6, 7 and 8 for extrapolation data curves at the center frequencies, 10 GHz, 15 GHz, and 95 GHz. Data sets for Table 2 show antenna Gain equivalency values and uncertainties for each antenna with serial number for each antenna. Data set for Table 3 shows polarization equivalency values and uncertainties for each antenna with serial number for each antenna. Table 4 shows uncertainty analysis for gain and polarization equivalency results.

The long-period radio transients are an emerging class of unusual astrophysical phenomena that generate bursts of radio waves at slow periodicities (minutes to hours). Their nature is mysterious and very little data exists toward the ~ten that are known (10-20 pulses is typical). As novel and rare transients, most radio observations carried out so far have consisted of Directors' Discretionary Time and Target-of-Opportunity requests. Consistent monitoring campaigns are challenging, as the sources only generate radio waves infrequently, making long dwells inefficient. Here we propose leveraging ASKAP's wide field-of-view to target three long-period radio transients in a single pointing, obtaining over 150 pulse measurements with 25 hours of observing time, in full polarisation, using CRACO and the correlator together to probe timescales of 100ms to tens of minutes. This will be a treasure trove for understanding the nature of these sources and will be the first consistent monitoring campaign at these frequencies.