Arbitrary Waveform Generator Research Articles

A detector-emulation method for realistic readout-electronics tests. A case study of VMM3a ASIC for sTGC detector.

We present a detector-emulation method for developing, optimizing, and testing front-end electronics for particle detectors under realistic experimental conditions. The method is capable of reproducing bipolar signals shape and amplitude, rates, pileup, and radiation backgrounds. By controlling the different components of the experimental environment, the method allows for the assessment of their individual and combined effects, which is difficult to achieve in test beam or experiment environment. The technique emulates the output current of AC coupled detector terminals for an experimental environment of interest, by combining a sequence of recorded or simulated signal waveforms. Voltage waveforms produced with off the shelf arbitrary waveform generators are converted to current by a simple circuit, which also accounts for the characteristic capacitance of the detector, and injected into the front-end electronics. We demonstrate the technique by applying it in the optimization and characterization of the front-end electronics of the sTGC detector for the ATLAS experiment.

Antiderivative Antialiasing for Arbitrary Waveform Generation

In the last decades many efficient methods have been proposed to generate waveforms with reduced aliasing, proving this field quite mature. However, the introduction of Antiderivative Antialiasing (AA) methods for the reduction of aliasing in nonlinear discrete-time processing, can shed a new light on bandlimited oscillators and provide a general method for dealing with aliasing in arbitrary waveforms generation. In this work we will first bridge the gap between AA methods and bandlimited waveform generation, and then show the flexibility of the recently introduced AA-IIR method for dealing with both classical synthesizer waveforms and arbitrary wavetables. We will show how AA methods can be used for periodic and non-periodic waveform generation, and provide an innovative AA-IIR method able to compute alias-reduced version of any waveform with arbitrary antialiasing filter order, without the effort of computing ad hoc analytical expressions. Antialiasing performance is compared with other well known methods, showing the effectiveness of the approach.

Low-Noise, High-Linearity Sine-Wave Generation Using Noise-Shaping Phase-Switching Technique

To develop a lower cost on-chip characterization solution for postsilicon validation, this article proposed a “noise-shaping phase-switching” technique on a sigma–delta modulated digital-to-analog converter (DAC) to realize a low-noise, high-linearity sinusoidal-wave generator. The proposed technique combines the fifth-order cascade of resonators with distributed feedback (CRFB) type delta–sigma modulation (DSM) and the two-way time-interleaving phase-switching harmonic distortion (HD) cancellation technique without additional cost. The theoretical analysis is verified with MATLAB and further implemented using a low-cost arbitrary waveform generator (AWG) as the output DAC. Compared with a nonideal 12-b DAC, the proposed technique achieved at least 2-dB enhancement in spurious-free dynamic range (SFDR) (measurement) while maintaining an improvement of at least 18 dB in the medium dynamic range (DR) (simulation) over the entire signal bandwidth.

Amplification of pulsed light with arbitrary frequency chirps on nanosecond timescales.

We have developed a system for producing amplified pulses of frequency-chirped light at 780nm on nanosecond timescales. The system starts with tunable cw laser light and employs a pair of fiber-based phase modulators, a semiconductor optical amplifier, and a tapered amplifier to achieve chirp rates exceeding 3 GHz/10ns and peak powers greater than 1W. Driving the modulators with an arbitrary waveform generator enables arbitrary chirp shapes, such as two-frequency linear chirps. We overcome the optical power limitations of the modulators by duty cycling and avoid unseeded operation of the tapered amplifier by multiplexing the chirped pulses with "dummy" light from a separate diode laser.

Supplementary comparison for the traceability of AC high voltage reference measuring systems up to 200 kV (EURAMET.EM-S33)

Main textThe intercomparison consisted of calibrating a High Voltage Travelling Reference Measuring System, TRMS, using peak and rms voltage values, at the frequency of 50 Hz and with voltages of 750 V, 1 kV, 40 kV, 80 kV, 120 kV, 160 kV and 200 kV.The TRMS consisted of a capacitive divider with fixed input and grounding leads, a coaxial cable, a HP 3458A digital multimeter and a computer with a printer. The TRMS had two ranges, 20 kV and 200 kV, depending on the low voltage arm connected to the high voltage capacitor. The TRMS included the low voltage digital multimeter, in such a way that the measuring error of high voltage TRMS should be measured to determine the scale factor of the high voltage divider. Intercomparison results are expressed as the scale factor of the travelling high voltage capacitive divider, the scale factor is dimensionless.Complementary low voltage measurements were also performed to check how the peak voltage is evaluated when harmonics or distortion are superimposed to sinusoidal waveforms. To evaluate this performance an arbitrary waveform generator was included among the travelling devices in such a way that it was possible to compare the peak voltage measured by the TRMS using the provided digital multimeter and the specific intercomparison software and the peak voltage measured by each participant.The coordinating laboratory was LCOE (Spain) and the participating institutes were LNE (France), VTT MIKES (Finland), RISE (Sweden), TÜBITAK UME (Türkiye), PTB (Germany), BIM (Bulgaria), INRiM (Italy), VSL (Netherlands), VNIMS (Russia) and LCOE (Spain).Results of the comparison proved the calibration and measurement capabilities, CMCs, of the participants in the field of high voltage AC measurement, especially when performing peak hv measurements up to 200 kV with expanded uncertainties in the range of 40 mV/V to 80 mV/V.The discrepancy between the results of the two labs claiming the lowest uncertainties, PTB and VTT, was on some measurements significantly larger than the respective uncertainties. One of these labs redesigned its measuring system and a subsequent bilateral comparison arranged between PTB and VTT solved the discrepancy.Undertaking the work collaboratively through EURAMET proved to be an excellent tool to compare calibration and measurement capabilities of NMI and DI, as well as an opportunity for several institutes to improve their CMCs.To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database https://www.bipm.org/kcdb/.The final report has been peer-reviewed and approved for publication by the CCEM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

Broadband and tunable optical frequency comb based on 1550 nm verticalcavity surface-emitting laser under pulsed current modulation and optical injection

Optical frequency combs (OFCs) each consist of a set of equally spaced discrete frequency components, and they have been widely applied to many fields such as metrology, optical arbitrary waveform generation, spectroscopy, optical communication, and THz generation. In this work, we propose a scheme for generating broadband and tunable OFCs based on a 1550 nm vertical-cavity surface-emitting laser (VCSEL) under pulsed current modulation and optical injection. Firstly, a pulsed electrical signal is utilized to drive a 1550 nm-VCSEL into the gain-switching state with a broad noisy spectrum. Next, a continuous optical wave is further introduced for generating broadband and tunable OFC. Under injection light with power of 18.82 µW and wavelength of 1551.8570 nm, and pulsed electrical signal with a frequency of 0.5 GHz and pulse width of 200 ps, an OFC with a bandwidth of 82.5 GHz and CNR of 35 dB is experimentally acquired, and the single sideband phase noise at the 0.5 GHz reaches –123.3 dBc/Hz at 10 kHz. Moreover, the influences of injection light wavelength, frequency and width of pulse electrical signal on the performance of generated OFC are investigated. The experimental results show that OFCs with different comb spacings can be obtained by varying the frequency of pulsed electrical signal. For the frequency of pulsed current signal varying in a range of 0.25 GHz–3 GHz, the bandwidth of generated OFCs can exceed 60 GHz through selecting optimized injection optical wavelength and width of pulse electrical signal.

Design of Gaussian modulator for continuous-variable quantum key distribution

The continuous-variable quantum key distribution experimental system requires the randomness and speed of a Gaussian modulator. We present the hardware design for a Gaussian random number (GRN) generator based on the Box–Muller method, which can be implemented on a field-programmable gate array (FPGA). An external high-speed true random number generator application-specific integrated circuit (ASIC) is used to this end. The ASIC operates faster and more independently compared with other Gaussian algorithms based on a linear feedback shift register. The trigonometric and logarithmic functions are calculated using the nonuniform piecewise linear approximation. The calculation of the Gaussian random modulus and phase value is realized using this hardware. Compared with an arbitrary waveform generator, the GRN can be uploaded to a computer to estimate the security key rate. Furthermore, the GRN generator accurately provides a Gaussian probability density function that passes the Jarque–Bera inspection and Lilliefors tests. The proposed FPGA-based system is demonstrated to convert eight-channel 320-Mbps uniform random numbers to 40-MHz 16-bit GRN in real time. Finally, the control of the optical module and Gaussian modulation is realized via the FPGA-based outputs of four dual-channel, 16-bit, 1-giga samples per second digital-to-analog converters.

Electro-optically derived millimeter-wave sources with phase and amplitude control

Integrated circuits are building blocks in millimeter-wave handsets and base stations, requiring nonlinear characterization to optimize performance and energy efficiency. Today's sources use digital-to-analog converters to synthesize arbitrary electrical waveforms for nonlinear characterization, but this approach demands even faster integrated circuits to increase the bandwidth to millimeter-waves. Optically derived sources are a potential path to generate precise millimeter-waves and arbitrary waveforms using additive frequency synthesis. In this work, we demonstrate optically derived millimeter-waves up to 99.2 GHz with phase and amplitude control that could be locked to an optical reference. Our approach uses a 1550 nm electro-optic frequency comb with a terahertz of bandwidth. A programmable spectral filter selects two wavelengths from the optical comb, illuminating a modified uni-traveling carrier photodiode on a coplanar waveguide. We then tune the phase and amplitude by varying the optical phase and amplitude in the programmable spectral filter. The result of our work is electro-optically derived millimeter-waves at (24.8, 49.6, 74.4, and 99.2) GHz with phase and amplitude control, enabling arbitrary repetitive waveform generation.

Optoelectronic Oscillator for Arbitrary Microwave Waveform Generation

An optoelectronic oscillator (OEO) for arbitrary microwave waveform generation based on Fourier domain mode-locking (FDML) is proposed. A reconfigurable optical waveform generator (OWG) is implemented via external electro-optical modulation, which serves as the optical source for the proposed OEO. The optical waveform from the OWG can be seen as a series of frequency-scanning optical wavelengths in the frequency domain. At any instant, the number of wavelengths can be from 0 to infinite. By setting the period of the optical waveform or its multiple equal to the cavity round-trip time, an FDML OEO implemented by a frequency-scanning microwave photonic filter (MPF) is realized based on the phase-modulation-to-intensity-modulation conversion using a phase modulator cascaded with a phase-shifted fiber Bragg grating. The scanning characteristics of the MPF changes according to the optical waveform, which can be utilized to generate low-phase-noise arbitrary microwave waveforms using the inherent low-phase-noise merit of an OEO. An experiment is performed. Linearly chirped microwave waveforms and non-linearly chirped microwave waveforms with a scanning bandwidth of 2 GHz, 2-level frequency hopping (FH) microwave waveforms with an FH range of 500 MHz, and 240- and 250-bit binary and quaternary phase-coded microwave waveforms are generated from the OEO. To the best of our knowledge, this is the first time that an OEO is proposed for arbitrary microwave waveform generation.

Science & technology trends in cognitive radar concept

Currently, human operators provide cognition in a radar system. However, advances in the “digitization” of radar front-ends, including digital arbitrary waveform generators (AWG) and advanced high performance embedded computing (HPEC) make it possible to vary all key radar parameters (power, pulse length, number of pulses, pulse repetition frequency (PRF), modulation, frequency, polarization) on a pulse-by-pulse basis within ns or ms and over a wide operating range. This timescale is much faster than the decision-making ability of a human operator. The cognitive-inspired techniques in radar, that are intensively developing last years, mimic elements of human cognition and the use of external knowledge to use the available system resources in an optimal way for the current goal and environment. Radar systems based on the perception-action cycle of cognition that senses the environment, learns relevant information from it about the target and the background and then adapts the radar to optimally satisfy the needs of the mission according to a desired goal are called cognitive radars. In the article, recent ideas and applications of cognitive radars were analyzed.

Efficient electro-optical modulation on thin-film lithium niobate: erratum.

In this erratum, we correct the corresponding results of our Letter [Opt. Lett.46, 1884 (2021)OPLEDP0146-959210.1364/OL.419597] due to the wrong impedance setting of the arbitrary waveform generator (AWG). The Letter still represents the significant advance despite the change of results.

IC-Based Neuro-Stimulation Environment for Arbitrary Waveform Generation

Electrical stimulation of the nervous system is commonly based on biphasic stimulation waveforms, which limits its relevance for some applications, such as selective stimulation. We propose in this paper a stimulator capable of delivering arbitrary waveforms to electrodes, and suitable for non-conventional stimulation strategies. Such a system enables in vivo stimulation protocols with optimized efficacy or energy efficiency. The designed system comprises a High Voltage CMOS ASIC generating a configurable stimulating current, driven by a digital circuitry implemented on a FPGA. After fabrication, the ASIC and system were characterized and tested; they successfully generated programmable waveforms with a frequential content up to 1.2 MHz and a voltage compliance between [−17.9; +18.3] V. The system is not optimum when compared to single application stimulators, but no embedded stimulator in the literature offers an equivalent bandwidth which allows the wide range of stimulation paradigms, including high-frequency blocking stimulation. We consider that this stimulator will help test unconventional stimulation waveforms and can be used to generate proof-of-concept data before designing implantable and application-dedicated implantable stimulators.

Simultaneous frequency and bandwidth doubling linearly chirped waveform generation based on cascaded phase modulator and dual-output dual-parallel Mach-Zehnder modulator

An approach to generate the linearly chirped microwave waveform with simultaneous frequency and bandwidth doubling by using cascaded phase modulator and dual-output dual-parallel Mach-Zehnder modulator (DO-DPMZM) is proposed. The lightwave emitted from a laser diode is firstly modulated by a splitting parabolic signal to realize a symmetric-triangle linear frequency sweeping light. The frequency sweeping light is then sent to a DO-DPMZM driving by a radio frequency (RF) signal. By properly setting the direct current biases of two sub-modulators, single sideband modulation is realized at each output of the DO-DPMZM. By introducing a time delay in one branch of the modulator’s outputs, a linearly chirped microwave waveform with both frequency and bandwidth doubling can be generated after optical-to-electrical conversion. The central frequency and bandwidth of the generated waveform can be easily adjusted by tuning the frequency of the RF signal and electrical coding signal of the arbitrary waveform generator. The linearly chirped microwave waveforms with bandwidth of 10 GHz and central frequency of 30 GHz or bandwidth of 12 GHz and central frequency of 40 GHz are numerically generated. Due to the simple structure and flexible tunability, the proposal may find applications in future high resolution radar systems.

Photonic generation of microwave arbitrary waveforms using stimulated Brillouin scattering and Sagnac loop

Photonic generation of microwave arbitrary waveforms using stimulated Brillouin scattering and Sagnac loop

Hardware for multi-superconducting qubit control and readout* *Project supported by the State Key Development Program for Basic Research of China (Grants Nos. 2017YFA0304300 and 2016YFA0300600), the Natural Science Foundation of Beijing, China (Grant No. Z190012), the Key-Area Research and Development Program of Guangdong Province, China (Grant No. 2020B0303030001), and the Strategic Priority Research Program of Chinese Academy of Sciences (Grant

We have developed an electronic hardware system for the control and readout of multi-superconducting qubit devices. The hardware system is based on the design ideas of good scalability, high synchronization and low latency. The system, housed inside a VPX-6U chassis, includes multiple arbitrary-waveform generator (AWG) channels, analog-digital-converter (ADC) channels as well as direct current source channels. The system can be used for the control and readout of up to twelve superconducting transmon qubits in one chassis, and control and readout of more and more qubit can be carried out by interconnecting the chassis. By using field programmable gate array (FPGA) processors, the system incorporates three features that are specifically useful for superconducting qubit research. Firstly, qubit signals can be processed using the on-board FPGA after being acquired by ADCs, significantly reducing data processing time and data amount for storage and transmission. Secondly, different output modes, such as direct output and sequential output modes, of AWG can be implemented with pre-encoded FPGA. Thirdly, with data acquisition ADCs and controlAWGs jointly controlled by the same FPGA, the feedback latency can be reduced, and in ourtest a 178.4 ns latency time is realized. This is very useful for future quantum feedback experiments. Finally, we demonstrate the functionality of the system by applying the system to the control and readout of a 10 qubit superconducting quantum processor.

Stimulated Brillouin scattering mitigation using optimized phase modulation waveforms in high power narrow linewidth Yb-doped fiber amplifiers.

We demonstrate the mitigation of stimulated Brillouin scattering (SBS) in a double-clad single mode Yb-doped optical fiber amplifier through external phase modulation of narrow linewidth laser radiation using optimized periodic waveforms from an arbitrary waveform generator. Such optimized phase modulation waveforms are obtained through a multi-objective Pareto optimization based on a comprehensive model for SBS in high power narrow linewidth fiber amplifiers using Brillouin parameters determined from controlled measurements. The ability of our approach to mitigate SBS is tested experimentally as a function of RMS linewidth of the modulated optical radiation, and we measure an enhancement in SBS threshold with respect to optical linewidth of ∼ 10 GHz-1. Furthermore, we discuss the dependence of the SBS threshold enhancement on key parameters such as the amplifier length and the period of the optimized waveforms. Through simulations we find that waveforms of sufficiently long periods and optimized for a relatively long fiber (10 m) are effective for SBS suppression for shorter fibers as well. We also investigate the effect of increase in the bandwidth and amplitude of the modulation waveform on the SBS threshold enhancement observed at higher optical linewidth.

Photonic arbitrary waveform generation based on the temporal Talbot effect.

In this paper, we propose a novel photonic approach for generating arbitrary waveform. The approach is based on the property of real-time Fourier transform in the temporal Talbot effect, where the spectrum of the modulating analog signal is converted into the output time-domain waveform in each period. We present a concise and strict theoretical framework to reveal the relationship of real-time Fourier transform between the optical signals before and after the dispersion. A proof-of-concept experiment is implemented to validate the presented theoretical model. We propose to generate symmetrical or asymmetrical arbitrary waveforms by using double-sideband or single-sideband modulation, respectively, which is verified by simulation results. It is shown that the given approach can be used to generate a repetition-rate multiplied optical pulse train with arbitrary waveform by simply using a multi-tone RF signal with appropriate frequencies and powers.

Precise Optical Modulation and Its Application to Optoelectronic Device Measurement

Optoelectronic devices which play important roles in high-speed optical fiber networks can offer effective measurement methods for optoelectronic devices including optical modulators and photodetectors. Precise optical signal modulation is required for measurement applications. This paper focuses on high-speed and precise optical modulation devices and their application to device measurement. Optical modulators using electro-optic effect offers precise control of lightwaves for wideband signals. As examples, this paper describes frequency response measurement of photodetectors using high-precision amplitude modulation and wavelength domain measurement of optical filters using fast optical frequency sweep. Precise and high-speed modulation can be achieved by active trimming which compensates device structure imbalance due to fabrication error, where preciseness can be described by on-off extinction ratio. A Mach-Zehnder modulator with sub Mach-Zehnder interferometors can offer high extinction-ratio optical intensity modulation, which can be used for precise optoelectronic frequency response measurement. Precise modulation would be also useful for multi-level modulation schemes. To investigate impact of finite extinction ratio on optical modulation, duobinary modulation with small signal operation was demonstrated. For optical frequency domain analysis, single sideband modulation, which shifts optical frequency, can be used for generation of stimulus signals. Rapid measurement of optical filters was performed by using an optical sweeper consisting of an integrated Mach-Zehnder modulator for optical frequency control and an arbitrary waveform generator for generation of a source frequency chirp signal.

Programmable, direct space-to-time picosecond resolution pulse shaper with nanosecond record.

We demonstrate a novel, to the best of our knowledge, extension of optical arbitrary waveform generation capable of picosecond resolution over nanosecond duration. The method, called space-time induced linearly encoded transcription for temporal optimization, is based on direct space-to-time pulse shaping and is extended here to single-mode output with a programmable temporal profile. We develop the theory of operation and discuss ultimate limits on resolution, record length, and efficiency. We report on the results of an experimental demonstration showing ∼1ps resolution over 600 ps.

Photonic Scheme for the Generation of Background-Free Phase-Coded Microwave Pulses and Dual-Chirp Microwave Waveforms

We propose a photonic scheme to generate binary phase-coded microwave pulses and dual-chirp microwave waveforms without baseband-modulated signals (background noise) based on a dual-polarization dual-drive Mach-Zehnder modulator (DP-DDMZM) which contains x-DDMZM and y-DDMZM at two different polarization states. A radio frequency (RF) signal from a microwave source is transferred into two differential RF signals and employed into one arm of x-DDMZM and one arm of y-DDMZM, while a baseband signal from an arbitrary waveform generator is divided by an electronic coupler and then driven into the two other arms of DP-DDMZM. By adjusting the phase differences between the x-DDMZM and the y-DDMZM, binary phase-coded pulses and dual-chirp signals without baseband-modulated signals are generated. The proposed scheme can eliminate the interference caused by baseband-modulated signals, and satisfy different radar applications for different frequency bands. Experimental results show that phase-coded signals at 15 GHz with the bit rates of 1 Gb/s and 2 Gb/s and dual-chirp signals at 10 GHz and 15 GHz with the time durations of 0.5 μs are successfully generated. The reported scheme is well analyzed in theory and verified by experiment.