Deep learning-based object detection algorithms enable the simultaneous classification and localization of any number of objects in image data. Many of these algorithms are capable of operating in real-time on high resolution images, attributing to their widespread usage across many fields. We present an end-to-end object detection pipeline designed for rare event searches for the Migdal effect, at real-time speeds, using high-resolution image data from the scientific CMOS camera readout of the MIGDAL experiment. The Migdal effect in nuclear scattering, critical for sub-GeV dark matter searches, has yet to be experimentally confirmed, making its detection a primary goal of the MIGDAL experiment. The Migdal effect forms a composite rare event signal topology consisting of an electronic and nuclear recoil sharing the same vertex. Crucially, both recoil species are commonly observed in isolation in the MIGDAL experiment, enabling us to train YOLOv8, a state-of-the-art object detection algorithm, on real data. Topologies indicative of the Migdal effect can then be identified in science data via pairs of neighboring or overlapping electron and nuclear recoils. Applying selections to real data that retain 99.7% signal acceptance in simulations, we demonstrate our pipeline to reduce a sample of 20 million recorded images to fewer than 1000 frames, thereby transforming a rare search into a much more manageable search. More broadly, we discuss the applicability of using object detection to enable data-driven machine learning training for other rare event search applications such as neutrinoless double beta decay searches and experiments imaging exotic nuclear decays.

The use of inverter-based motor controllers that can generate fast voltage level transitions is increasing in the field of electric drive systems because of their ability to achieve higher efficiency. However, the fast voltage transitions, dv/dt's, are prone to generate bearing currents and cause overvoltages that may harm the electric motor. An LC filter applied between the inverter and the motor terminals can reduce the dv/dt's. However, the LC filter will cause overvoltage due to resonance but this can be overcome by introducing an extra pulse at each pulse-width modulation (PWM) transition. The timing of this extra pulse is crucial for suppressing the resonance, but due to nonlinearities in a real system, the time instants may vary over time and are thus in need of control. In this study, an analytical expression for the optimal pulse location and duration is derived and we propose a control algorithm that continuously calculates the optimal pulse switch time instants based on the measured output voltage. The control algorithm can handle sudden system disturbances and a Monte Carlo simulation is performed to evaluate the performance of the algorithm. This hybrid filter successfully reduces dv/dt's at the motor terminals while simultaneously eliminating overvoltages due to the filter resonance.

This paper presents a feasibility study of an ultrasonic backscatter communication system designed for low-power, short-range data transmission, suitable for applications in IoT, biomedical implants, and underwater sensor networks. Our proposed system utilizes a very low power passive network to encode information by modulating the reflection properties of the backscatter medium. We demonstrate through experimental analysis the effective data transmission and detection. The key contribution of this study includes the development of a practical experimental setup using ultrasonic transducers, backscatter modulators, alongside signal processing techniques for optimal data extraction. Results indicate the successful data transmission and detection for a limited number of bits in a very high SNR regime, showcasing the performance of the transmission protocol.

This paper presents electromagnetic simulations of a wireless power transfer system suitable for a monitoring system for detection of solder fatigue in power semiconductor modules. Power is provided wirelessly from a printed spiral coil on a printed circuit board to a silicon chip with an on-chip coil. We use and adapt a known gradient-ascent-based optimisation algorithm to obtain suitable coil geometries. For a frequency of 433 MHz, the simulations show an efficiency of -34.7 dB which we conclude is sufficient for the proposed monitoring system.

Efficient beamforming of phased-array antennas requires that the phase delay of each channel is accurately known. One technique for achieving this is to distribute a calibration or local-oscillator reference signal through a delay-insensitive signal distribution network. In this paper, we propose using passive hierarchical signal distribution networks to distribute such signals, a method that scales significantly better with the size of the array than existing signal distribution methods. We analyze the impact of impedance variations within the network on the phase accuracy and propose a calibration front-end architecture. This front end also enables the return loss and coupling between antennas to be monitored for diagnostic purposes. We present an implementation of this front end that was applied to a small prototype antenna array, and show that this implementation exhibited low sensitivity to delays within the calibration network, reduced the temperature-dependent phase error of the front ends substantially, and can be used for performing antenna return-loss measurements

This paper presents an encapsulation concept that enables the construction of small wireless measurement systems that can operate in industrial environments with ambient temperatures of up to 1200°C. To maximize operational time and minimize size, a layer of thermal insulation is combined with water absorbed in a porous material in the core of the device. The simulated operating time before all of the frozen water at 0?C has transformed into steam at 100°C when the ambient temperature of the device was 1200°C is 21 minutes for a sphere with an outer radius of 4 cm. If the outer radius is increased to 10 cm the simulated operating time increases to 125 minutes. Measurements were performed to validate the design. When a sphere with a radius of 4 cm was subjected to an oven temperature of 1200°C the device held the core temperature at or below 101°C for a total of 25 minutes. The time to reach the boiling point of the water was 9 minutes. Thereafter, the temperature was held constant at 100 +/- 1°C for an additional 16 minutes whereafter a rapid rise in temperature took place once all water had evaporated.

This paper analyses the frequency limitations of an active rectifier for RFID applications that has been optimised for 13.56 MHz. The rectifier utilises an active MOS diode with threshold cancellation and a control scheme to reduce reverse leakage. The rectifier is implemented in AMS 0.35 µm CMOS and simulated in Cadence Spectre. For an input voltage of 2 V and an output current of 20 µA, a power and voltage conversion efficiency of 83 % and 89 %, respectively, are achieved at 13.56 MHz. We show that reducing the width of the main MOS transistor from 90 to 60 µm improves the upper frequency limit, but beyond 30 MHz the finite speed of the threshold cancellation control circuit limits the efficiency of the rectifier circuit.

A front-end architecture for inductive RFID transponders using multiple coil antennas for reduced ori- entation sensitivity is presented. The front-end uses multiple antennas for reception and one antenna for transmission. A select function identifies the antenna that is most favorably oriented toward the reader for transmission by comparing the DC charge-up phases of multiple DC generation blocks during power-up of the transponder. CMOS circuit design and simulation results of a front-end for 125 kHz FSK modulation are presented for a pulsed RFID system as well as an archi- tecture for cascaded DC generation. This paper also includes an example of a coil antenna for spherical transponders using three independent orthogonal windings.

The response and the reaction of the brain system to hypoxia is a vital research subject that requires special instrumentation. With this research subject in focus, a new multifunctional lab-on-a-chip (LOC) system with control over the oxygen content for studies on biological cells was developed. The chip was designed to incorporate the patch clamp technique, optical tweezers and absorption spectroscopy. The performance of the LOC was tested by a series of experiments. The oxygen content within the channels of the LOC was monitored by an oxygen sensor and verified by simultaneously studying the oxygenation state of chicken red blood cells (RBCs) with absorption spectra. The chicken RBCs were manipulated optically and steered in three dimensions towards a patch-clamp micropipette in a closed microfluidic channel. The oxygen level within the channels could be changed from a normoxic value of 18% O 2 to an anoxic value of 0.0-0.5% O 2. A time series of 3 experiments were performed, showing that the spectral transfer from the oxygenated to the deoxygenated state occurred after about 227 ± 1 s and a fully developed deoxygenated spectrum was observed after 298 ± 1 s, a mean value of 3 experiments. The tightness of the chamber to oxygen diffusion was verified by stopping the flow into the channel system while continuously recording absorption spectra showing an unchanged deoxygenated state during 5400 ± 2 s. A transfer of the oxygenated absorption spectra was achieved after 426 ± 1 s when exposing the cell to normoxic buffer. This showed the long time viability of the investigated cells. Successful patching and sealing were established on a trapped RBC and the whole-cell access (Ra) and membrane (Rm) resistances were measured to be 5.033 ± 0.412 M Ω and 889.7 ± 1.74 M Ω respectively.

The design of a 450 nW bandgap temperature sensor in the 0 to 175 °C range is presented. The design demonstrates a leakage current compensation technique that is useful for low-power designs where transistor performance is limited. The technique mitigates the effects of leakage in Brokaw bandgap references by limiting the amount of excess current that is entering the bases of the main bipolar pair due to leakage. Using this technique, Monte Carlo simulations show an improvement factor of 7.6 for the variation of the temperature sensitivity over the full temperature range. For the variation of the reference voltage, Monte Carlo simulations show an improvement factor of 2.3.Sensors built using this technique can be used to accurately monitor the temperature of power semiconductors since wireless temperature sensors become feasible with sufficiently low power consumption.

The design of a 450 nW bandgap temperature sensor in the 0 to 175 °C range is presented. The design demonstrates a leakage current compensation technique that is useful for low power designs where transistor performance is limited. The technique mitigates the effects of leakage in Brokaw bandgap references by limiting the amount of excess current that is entering the bases of the main bipolar pair due to leakage. Using this technique, Monte Carlo simulations show an improvement factor of 7.6 for the variation of the temperature sensitivity over the full temperature range. For the variation of the reference voltage, Monte Carlo simulations show an improvement factor of 2.3. Sensors built using this technique can be used to accurately monitor the temperature of power semiconductors since wireless direct-contact temperature sensors become feasible with sufficiently low power consumption.