Programmable Generator Research Articles

High-sensitivity pump-probe spectroscopy with a dual-comb laser and a PM-Andi supercontinuum

Amplifier-based pump-probe systems, while versatile, often suffer from complexity and low measurement speeds, especially when probing samples require low excitation fluences. To address these limitations, we introduce a pump-probe system that leverages a 60-MHz single-cavity dual-comb oscillator and an ultra-low noise supercontinuum. The setup can operate in equivalent time sampling or in programmable optical delay generation modes. We employ this system to study the wavelength-dependent excited-state dynamics of the non-fullerene electron acceptor Y6, a compound of interest in solar cell development, with excitation fluences as low as 1 nJ/cm2, well below the onset of nonlinear exciton annihilation effects. Our measurements reach a shot-noise limited sensitivity in differential transmission of 3.4·10–7. The results demonstrate the system’s potential to advance the field of ultrafast spectroscopy.

Embedded systems as programmable square wave generator in wireless power transfer

<span>This study focuses on the design and development of programmable frequency generator using embedded devices that are able to produce square wave signals in the wireless power transfer (WPT) transmitter. We validate the accuracy of the output signal by measuring distance error. We validate that our system can change and sweep the frequency and produce high power by measuring the absorbed power in the load. We conduct the frequency sweep analysis to find optimal frequency and the frequency splitting phenomenon. The experiments show that the system can produce and sweep the square wave signals with less than 1% error. We also find that the frequency splitting occurred when distance among two coils in the range 0.5-6.5 cm and the splitting disappeared when the distance is above 7.5 cm. The frequency splitting shows that the measured optimum frequency differs from the calculation. The difference confirms that the programmable frequency generator is needed to adjust the frequency that can transfer maximum power to the load.</span>

Programmable generation of counterrotating bicircular light pulses in the multi-terahertz frequency range

The manipulation of solid states using intense infrared or terahertz light fields is a pivotal area in contemporary ultrafast photonics research. While conventional circular polarization has been well explored, the potential of counterrotating bicircular light remains widely underexplored, despite growing interest in theory. In the mid-infrared or multi-terahertz region, experimental challenges lie in difficulties in stabilizing the relative phase between two-color lights and the lack of available polarization elements. Here, we successfully generated phase-stable counterrotating bicircular light pulses in the 14–39 THz frequency range circumventing the above problems. Employing spectral broadening, polarization pulse shaping with a spatial light modulator, and intra-pulse difference frequency generation leveraging a distinctive angular-momentum selection rule within the nonlinear crystal, we achieved direct conversion from near-infrared pulses into the designed counterrotating bicircular multi-terahertz pulses. Use of the spatial light modulator enables programmable control over the shape, orientation, rotational symmetry, and helicity of the bicircular light field trajectory. This advancement provides a novel pathway for the programmable manipulation of light fields, and marks a significant step toward understanding and harnessing the impact of tailored light fields on matter, particularly in the context of topological semimetals.

Some Solutions to Improve Programming Skills for Information Technology Students at Tan Trao University

In the rapidly evolving field of Information Technology, proficient programming skills are paramount for students aspiring to excel in their careers. This study investigates the current state of programming competencies among IT students at Tan Trao University, identifies the challenges they face, and proposes targeted solutions to enhance their programming capabilities. Utilizing a mixed-methods approach, we gathered data through surveys, interviews, and performance assessments, revealing significant gaps in foundational knowledge, practical application, and problem-solving skills. Based on these findings, we recommend a multifaceted strategy that includes curriculum enhancement, hands-on coding workshops, peer mentoring programs, and the integration of industry-relevant projects. These solutions aim to create a robust learning environment that not only improves technical skills but also fosters critical thinking and collaboration. The implementation of these strategies is expected to significantly elevate the programming proficiency of IT students at Tan Trao University, preparing them to meet the demands of the tech industry and contribute innovatively to their future workplaces. This research underscores the urgent need for educational institutions to adapt and evolve their teaching methodologies to cultivate the next generation of skilled programmers.

Automated design of embedded digital signal processing systems on SOC platform

The object of the study is the procedures for automated design and analysis of digital signal processing algorithms on the SoC technology platform. The subject of the study is models, methods and procedures for designing and optimal selection of SoC components for the implementation of digital signal processing algorithms for audio spectrum. The aim of the study is to develop models and procedures for determining the possibilities of a compromise distribution of signal processing algorithm computations in the cycle of computer-aided design on the SoC technology platform in terms of performance and the feasibility of using hardware and software algorithms realization. The article solves the following tasks: consideration of the procedures for interacting the processor core with programmable logic as part of system-on-chip systems; development of procedures for computer-aided design and analysis of signal processing systems using programming languages and hardware description languages for the implementation of embedded systems. The following methods are being used: implementation of digital signal processing algorithms in the C programming language and high-level synthesis tools for realizing IP blocks, diagnostic experiment by generating test signal patterns, and analysis of the processing results at the system output. The results achieved. Based on the analysis of the procedures for the interaction of the processor core and programmable logic on the selected SoC platform, a model of the audio spectrum signal processing system is designed. The practical implementation was performed based on the Vivado/Vitis/Vitis HLS CAD tool stack. The proposed model was verified using a programmable test signal generator and analyzing the obtained characteristics of digital filters at the system output. Conclusions. The article analyzes the principles of designing embedded information processing systems implemented in system-on-chip. The principles of building and analyzing digital signal processing systems based on system-on-chip containing programmable logic and processor parts are considered. The developed methods have been tested on the algorithms of CIC and FIR filters on the technological platform of SoC FPGA of the ZYNQ-7000 family of Xilinx company.

EO nonlinear function generator.

An electro-optical programmable nonlinear function generator (PNFG) is developed on a multimode waveguide with four parallel thermal electrodes. The current on one electrode is chosen as the input, while the rest serve as function-defining units to modulate the multimode interference. The electro-thermo-optical effects are analyzed step by step and the impact on the eigenmode properties is derived. It shows that the optical output power variation by altered interference, in response to the input current, manifests as a complex ensemble of functions in general. The PNFG aims to find the special setting under which such relation can be simplified into some basic functions. Through an optimization program, a variety of such functions are found, including Sigmoid, SiLU, and Gaussian. Furthermore, the shape of these functions can be adjusted by finetuning the defining units. This device may be integrated in a large-scale photonic computing network that can tackle complex problems with nonlinear function adaptability.

A new X‐band frequency up‐converter design for LEO satellite ground station utilizing a single superheterodyne

AbstractIn this work, the advancing wireless revolution (AWR) modeling and Microwave Office tools are used to develop and execute a broadband up‐converter system. Before sending the input frequency to the antenna interface, a radio frequency block upconverts it once to the appropriate frequency level. Mixing blocks, oscillators, amplifiers, step attenuators, isolators, and filters are included. The input frequency (IF) band is MHz, while the output frequency (radio frequency [RF]) band is MHz. The usage of attenuators increases the dramatic range of the circuit. It is a one‐stage up‐conversion circuit that combines the IF band in one pass to create the appropriate RF spectrum. Here, a single phase‐locked oscillator is employed at the local oscillator port of the mixers, while the other is a programmable frequency generator that generates X‐band frequency channels with a 10 MHz spacing.

Fully Integrated 24-GHz 1TX-2RX Transceiver for Compact FMCW Radar Applications.

A fully integrated 24-GHz radar transceiver with one transmitter (TX) and two receivers (RXs) for compact frequency modulated continuous wave (FMCW) radar applications is here presented. The FMCW synthesizer was realized using a fractional-N phase-locked loop (PLL) and programmable chirp generator, which are completely integrated in the proposed transceiver. The measured output phase noise of the synthesizer is -80 dBc/Hz at 100 kHz offset. The TX consists of a three-bit bridged t-type attenuator for gain control, a two-stage drive amplifier (DA) and a one-stage power amplifier (PA). The TX chain provides an output power of 13 dBm while achieving <0.5 dB output power variation within the range of 24 to 24.25 GHz. The RX with a direct conversion I-Q structure is composed of a two-stage low noise amplifier (LNA), I-Q generator, mixer, transimpedance amplifier (TIA), a two-stage biquad band pass filter (BPF), and a differential-to-single (DTS) amplifier. The TIA and the BPF employ a DC offset cancellation (DCOC) circuit to suppress the strong reflection signal and TX-RX leakage. The RX chain exhibits an overall gain of 100 dB. The proposed radar transceiver is fabricated using a 65 nm CMOS technology. The transceiver consumes 220 mW from a 1 V supply voltage and has 4.84 mm2 die size including all pads. The prototype FMCW radar is realized with the proposed transceiver and Yagi antenna to verify the radar functionality, such as the distance and angle of targets.

Plasma synthetic jet actuator array driven by a programmable triggered Marx high-voltage generator

A plasma synthetic jet (PSJ) actuator array driven by a self-triggered Marx high-voltage generator can simultaneously actuate multichannel PSJ actuators to form jet arrays; however, the discharge frequency cannot be controlled by programmable electrical signals. To address this, programmable high-voltage pulses are used to trigger a Marx high-voltage generator and regulate the discharge frequency of the PSJ actuator array. The electrode gap range for achieving a programmable triggered discharge is determined, and typical discharge images and basic discharge characteristics are obtained. The effects of trigger frequency and voltage amplitude on the discharge frequency are studied. The high-speed Schlieren technique is used to obtain flow-field characteristics of five-channel PSJ actuators under a programmable triggered state. The programmable triggered Marx high-voltage generator can achieve programmable control of the discharge frequency with an approximate linear control range of 10–30 Hz and a nonlinear saturation range of 30–100 Hz. In the approximate linear control range, the discharge frequency increases almost linearly with trigger frequency under different trigger voltage amplitudes. One of the channels of the five-channel synthetic jet actuators achieves the highest jet height and speed of 70 m/s, while those of the others are similar but slightly lower. There is no significant decrease in the jet height or speed of the five-channel PSJ actuators with the increase in the trigger frequency, which is beneficial for flow-control applications.

Photonic-Assisted Programmable Ultra-Wideband Frequency-Modulated Continuous-Wave Generator

Photonic-Assisted Programmable Ultra-Wideband Frequency-Modulated Continuous-Wave Generator

Programmable Generator of UWB Bipolar Voltage Pulses with Variable Waveforms

Programmable Generator of UWB Bipolar Voltage Pulses with Variable Waveforms

Gender dimension in STEM education in the Republic of Moldova: efforts and trends

By encouraging girls and women to develop and maintain an interest in STEM subjects, we are preparing the next generation of researchers, engineers, scientists and programmers to meet the growing demand for skilled STEM professionals. Current and future jobs and societal challenges require and will increasingly require a wide range of skills such as teamwork, intercultural competence, empathy, creativity, problem solving and independent non-linear thinking. Accordingly, we must ensure that women and girls are widely represented at all levels as we move forward. It is more important than ever that we eliminate stereotypes and biases and promote women and girls who want to pursue STEM careers.

The learnable CPG model based on Wilson-Cowan oscillator

The central pattern generator (CPG) is a micro circuit in neural system and it can generate rhythmic signals to regulate locomotion. The researchers have investigated the features of the CPG, and they have paid more attentions to the the programmable characteristic. In this address, a new learnable CPG based on Wilson-Cowan oscillator is established. The sine signal, the complex signal, the chaotic signal and angles of compass-like robot are used as input to test the new programmable central pattern generator. The simulations present that the learnable CPG has the ability to learn different signals effectively. These results are the significant contribution to the research of the programmable CPG.

A Capacitive Computing-In-Memory Circuit With Low Input Loading SRAM Bitcell and Adjustable ADC Input Range

We present a 9T1C SRAM cell-based capacitive computing-in-memory circuit for neural network computation. The proposed design improves tolerance against process variation with a smaller cell area compared to previous capacitive SRAM CIM designs while inheriting the advantage of capacitive SRAM CIM hardware such as the linearity in multiply-accumulate (MAC) results and suppression of the static readout current. We also demonstrate a compact and low-power ADC for CIM readout, which improves the energy efficiency significantly. Finally, we demonstrate a programmable on-chip ADC reference voltage generator circuit for adjusting the ADC input range using bitcell replica arrays. The proposed circuit reduces the ADC bit-resolution requirement by considering the distribution of MAC results, and also helps to address the effect of the parasitic bitline capacitance. Measurement results show that a 128×128 macro fabricated in a 28 nm CMOS achieves 1519.5 TOPS/W at 0.7 V.

Ultra‐efficient fully programmable membership function generator based on independent double‐gate FinFET technology

SummaryThis paper demonstrates an ultra‐efficient, fully programmable membership function generator (MFG) utilizing independent double‐gate (IDG) FinFET technology. The proposed MFG can produce s‐shaped, z‐shaped, triangular, and trapezoidal membership functions. By employing only six transistors, the designed MFG provides full controllability over the height, position, width, and slope of the generated waveforms. Without using any additional transistor and changing the dimensions, the proposed MFG can calibrate the slope of the output based on the back‐gate bias voltage of the IDG‐FinFETs. According to our extensive simulations, the proposed MFG shows promising improvements in transistor count (70%), power‐delay‐product (PDP) (80%), and maximum absolute error (61%) as compared with its state‐of‐the‐art counterparts. To benchmark the functionality of the proposed MFG in practical applications, our generated membership function is exploited as the neuron's activation function in a multilayer perceptron (MLP) neural network. The simulation results indicate that the training process of the simulated MLP with the proposed MFG closely tracks the results obtained from the ideal MLP with the sigmoid activation function. A figure of merit (FoM) is defined considering the hardware efficiency and accuracy of the neural networks to evaluate the entire performance of the proposed MFG. The FoM simulations demonstrate that the proposed MFG presents an excellent trade‐off between hardware performance and accuracy in neural network applications. Our results emphasize that the proposed MFG is a potential candidate for designing high‐performance on‐chip neural networks.

A high-performance and ultra-efficient fully programmable fuzzy membership function generator using FinFET technology for image enhancement

In fuzzy systems, efficient programmable membership function generators (MFGs) are the canonical point for the fuzzification process. This work demonstrates a high-performance programmable MFG using 7 nm FinFET technology. The proposed MFG can generate S-shaped, Z-shaped, Gaussian-shaped, and Generalized Bell-shaped membership functions. The proposed design employs 14 FinFETs to control the produced waveforms’ position, height, width, and slope. According to the simulations, the proposed MFG offers remarkable improvements in transistor count (39%), power-delay product (PDP) (54%), absolute error (45%), and root mean square error (36%) compared to the previous MFGs. The proposed design has been utilized for image enhancement to evaluate the performance of the proposed MFG in realistic environments. The image enhancement simulation results indicate a higher peak signal-to-noise ratio (PSNR) and structural similarity index metric (SSIM) than previous related works. A figure of merit (FoM) is defined considering the image enhancement quality metrics and circuit efficiency to benchmark the entire performance of the proposed MFG. The FoM simulations demonstrate that the proposed design shows an excellent trade-off between the circuit performance and image enhancement quality. Our results confirm that the proposed MFG is suitable for developing high-performance on-chip image processing applications.

Configurable Pseudo Noise Radar Imaging System Enabling Synchronous MIMO Channel Extension.

In this article, we propose an evolved system design approach to ultra-wideband (UWB) radar based on pseudo-random noise (PRN) sequences, the key features of which are its user-adaptability to meet the demands provided by desired microwave imaging applications and its multichannel scalability. In light of providing a fully synchronized multichannel radar imaging system for short-range imaging as mine detection, non-destructive testing (NDT) or medical imaging, the advanced system architecture is presented with a special focus put on the implemented synchronization mechanism and clocking scheme. The core of the targeted adaptivity is provided by means of hardware, such as variable clock generators and dividers as well as programmable PRN generators. In addition to adaptive hardware, the customization of signal processing is feasible within an extensive open-source framework using the Red Pitaya® data acquisition platform. A system benchmark in terms of signal-to-noise ratio (SNR), jitter, and synchronization stability is conducted to determine the achievable performance of the prototype system put into practice. Furthermore, an outlook on the planned future development and performance improvement is provided.

An Area- and Energy-Efficient Spiking Neural Network With Spike-Time-Dependent Plasticity Realized With SRAM Processing-in-Memory Macro and On-Chip Unsupervised Learning.

In this article, we present a spiking neural network (SNN) based on both SRAM processing-in-memory (PIM) macro and on-chip unsupervised learning with Spike-Time-Dependent Plasticity (STDP). Co-design of algorithm and hardware for hardware-friendly SNN and efficient STDP-based learning methodology is used to improve area and energy efficiency. The proposed macro utilizes charge sharing of capacitors to perform fully parallel Reconfigurable Multi-bit PIM Multiply-Accumulate (RMPMA) operations. A thermometer-coded Programmable High-precision PIM Threshold Generator (PHPTG) is designed to achieve low differential non-linearity (DNL) and high linearity. In the macro, each column of PIM cells and a comparator act as a neuron to accumulate membrane potential and fire spikes. A simplified Winner Takes All (WTA) mechanism is used in the proposed hardware-friendly architecture. By combining the hardware-friendly STDP algorithm as well as the parallel Word Lines (WLs) and Processing Bit Lines (PBLs), we realize unsupervised learning and recognize the Modified National Institute of Standards and Technology (MNIST) dataset. The chip for the hardware implementation was fabricated with a 55 nm CMOS process. The measurement shows that the chip achieves a learning efficiency of 0.47 nJ/pixel, with a learning energy efficiency of 70.38 TOPS/W. This work paves a pathway for the on-chip learning algorithm in PIM with lower power consumption and fewer hardware resources.

Rapid-Scan Nonlinear Time-Resolved Spectroscopy over Arbitrary Delay Intervals

Femtosecond dual-comb lasers have revolutionized linear Fourier-domain spectroscopy by offering a rapid motion-free, precise, and accurate measurement mode with easy registration of the combs beat note in the radio frequency domain. Extensions of this technique already found application for nonlinear time-resolved spectroscopy within the energy limit available from sources operating at the full oscillator repetition rate. Here, we present a technique based on time filtering of femtosecond frequency combs by pulse gating in a laser amplifier. This gives the required boost to the pulse energy and provides the flexibility to engineer pairs of arbitrarily delayed wavelength-tunable pulses for pump–probe techniques. Using a dual-channel millijoule amplifier, we demonstrate programmable generation of both extremely short, fs, and extremely long (&gt;ns) interpulse delays. A predetermined arbitrarily chosen interpulse delay can be directly realized in each successive amplifier shot, eliminating the massive waiting time required to alter the delay setting by means of an optomechanical line or an asynchronous scan of 2 free-running oscillators. We confirm the versatility of this delay generation method by measuring χ (2) cross-correlation and χ (3) multicomponent population recovery kinetics.

A novel stochastic model for flexible unit commitment of off-grid microgrids

This work proposes a novel two stage stochastic optimization approach for the Energy Management System (EMS) of MicroGrids (MG). It combines the scenario-based uncertainty characterization with the use of piecewise affine correction rules for the recourse decision. These rules are used by the EMS to set the commitment status of the programmable generators and to correct the storage management as a function of the realization of the uncertainty, measured in real-time. The novel stochastic model is integrated in a hierarchical EMS, based on two control layers: the first one employs the proposed stochastic approach to determine the daily strategic scheduling of the MG, and the second layer optimizes the real-time dispatch.. The proposed EMS is applied to a real-world case study of a rural MG. Results indicate that the proposed EMS outperforms state-of-the-art optimization approaches in terms ofservice reliability (99.8%) and fuel efficiency. Moreover, rolling horizon simulations of the proposed stochastic model showed 100% reliability, and 30% of fuel cost savings with respects to state-of-the-art methods. The novel EMS is then deployed on a laboratory-scale microgrid (Multi-Goods MicroGrid Laboratory, MG2lab), demonstrating secure and economic operations. A comparative analysis is made with respect to deterministic and standard stochastic two-stage approaches; the proposed solution outperforms the other models during real operations, with savings of fuel cost up to almost 10%.