25 papers · ranked by Valyu relevance
Victor Lazzarini, Joseph Timoney
Frequency modulation (FM) and phase modulation (PM) are well-known synthesis methods, which have been deployed widely in musical instruments. More recently, some synthesisers have implemented direct forms of FM (as opposed to PM), allowing, at least as part of their design, for higher-order modulation topologies.…
Parthasarathy, Rishab, Michael Popik, Noah Haefner
In this project, we wanted to discover an analog topology that could effectively convert amplitude-modulated (AM) signals to frequency-modulated (FM) signals, while also ensuring that both sets of signals were within their respective radio frequency (RF) bands. To that end, an effective topology for doing so was…
Kelly K Chong, Alex G Dunlap, Dorottya B Kacsoh, Robert C Liu
Frequency modulations are an inherent feature of many behaviorally relevant sounds, including vocalizations and music. Changing trajectories in a sound’s frequency often conveys meaningful information, which can be used to differentiate sound categories, as in the case of intonations in tonal languages. However, it is…
David Samuel Rose, Aleksandar Opančar, Štěpán Zelníček, Veronika Šromová + 1 more
Kilohertz-frequency (kHz) electrical stimulation (1–100 kHz) is emerging as a powerful tool in both invasive and non-invasive neurostimulation applications, including functional electrical stimulation, spinal cord stimulation, and non-invasive brain stimulation. Most commonly these paradigms rely on amplitude…
Damián Dellavale, Osvaldo Matías Velarde, Germán Mato, Eugenio Urdapilleta
Cross-frequency coupling (CFC) refers to the non linear interaction between oscillations in different frequency bands, and it is a rather ubiquitous phenomenon that has been observed in a variety of physical and biophysical systems. In particular, the coupling between the phase of slow oscillations and the amplitude of…
Rao Farhat Masood
In this paper, introduced below are the concepts of digital modulation used in many communication systems today. Techniques described include quadrature phase shift keying (QPSK) and quadrature amplitude modulation (QAM) and how these techniques can be used to increase the capacity and speed of a wireless network.…
Michael G Ruppert, David M Harcombe, Michael R P Ragazzon, S O Reza Moheimani + 2 more
'S O Reza Moheimani' 'Andrew J Fleming' 'Thilo Glatzel'] In this review paper, traditional and novel demodulation methods applicable to amplitude-modulation atomic force microscopy are implemented on a widely used digital processing system. As a crucial bandwidth-limiting component in the z-axis feedback loop of an…
Azalía G. Gil, Alfonso T. Muriel-Barrado, Mario Pérez-Escribano, Carlos Molero + 1 more
This paper presents the analysis, design, fabrication, and experimental validation of a dual-mode frequency/amplitude modulator based on a time-modulated varactor diode. By exploiting the varactor as a time-varying capacitor in combination with an operational amplifier configured as an inverting integrator and a…
Koichi Maezawa, Masayuki Mori, Hiroya Andoh, Guillermo Villanueva
Frequency delta-sigma modulator (FDSM) employing a variable frequency oscillator is a novel replacement of the classical delta-sigma modulators. This is advantageous for application to sensors, because an ADC can be intrinsically integrated with the sensors. We have already proposed to use this technique to various…
H. Schmickler
Depending on the application people use time-domain or frequency-domain signals in order to measure or describe processes. First we will look at the definition of these terms, produce some mathematical background and then apply the tools to measurements made in the accelerator domain. We will first look at signals…
Weiwei Yang, Xingyu Jia, Jingyi Wang, Xinlun Cai + 2 more
Frequency-modulated lasers (FMLs) are widely used in spectroscopy, biology, and LiDAR. These applications' performance highly depends on the fast and precise tracking of the FMLs' absolute frequencies, which remains a challenge. Here we demonstrated integrated lithium niobate electro-optic frequency combs with…
Anna-Katharina R. Bauer, Freek van Ede, Andrew J. Quinn, Anna C. Nobre
At any given moment our sensory systems receive multiple, often rhythmic, inputs from the environment. Processing of temporally structured events in one sensory modality can guide both behavioural and neural processing of events in other sensory modalities, but whether this occurs remains unclear. Here, we used human…
Jonathan Regev, Helia Relaño-Iborra, Johannes Zaar, Torsten Dau
The processing and perception of amplitude modulation (AM) in the auditory system reflect a frequency-selective process, often described as a modulation filterbank. Previous studies on perceptual AM masking reported similar results for older listeners with hearing impairment (HI) and young listeners with normal hearing…
Stefan Preußler, Gilda Raoof Mehrpoor, Thomas Schneider
Sampling is the first step to convert an analogue optical signal into a digital electrical signal. The latter can be further processed and analysed by well-known electrical signal processing methods. Optical pulse sources like mode-locked lasers are commonly incorporated for all-optical sampling, but have several…
Kiwon Rhee, Jaeyoung Baik, Changhoon Song, Hyun-Chool Shin + 1 more
'Jun Chen'] The importance of information gathering is emphasized to minimize casualties and economic losses in warfare. Through electronic warfare, which utilizes electromagnetic waves, it is possible to discern the enemy’s intentions and respond accordingly, thereby leading the battle advantageously. Consequently…
Keum-Won Ha, Jeong-Yun Lee, Jeong-Geun Kim, Donghyun Baek
Recently, studies have been actively carried out to implement motion detecting sensors by applying radar techniques. Doppler radar or frequency-modulated continuous wave (FMCW) radar are mainly used, but each type has drawbacks. In Doppler radar, no signal is detected when the movement is stopped. Also, FMCW radar…
Andrew J Harvie, Surendra K Yadav, John C de Mello
We report a sensitive, fixed-wavelength, lock-in-based optical detector built from a light-emitting diode, two colour filters, a photodetector, a small number of discrete analogue components, and a low-cost microcontroller development board. We describe the construction, operating principle, use and performance of the…
Jason Samaha, Michael X Cohen
Oscillatory neural dynamics are highly non-stationary and require methods capable of quantifying time-resolved changes in rhythmic activity in order to understand neural function. Recently, a method termed ‘frequency sliding’ was introduced to estimate the instantaneous frequency of oscillatory activity, providing a…
Matthias Grotevent, Claudio U. Hail, Sergii Yakunin, Dominik Bachmann + 4 more
Infrared light detection enables diverse technologies ranging from night vision to gas analysis. Emerging technologies such as low-cost cameras for self-driving cars require highly sensitive, low-cost photodetector cameras with spectral sensitivities up to wavelength of 10 um. For this purpose, colloidal quantum dot…
Authors not listed
This paper formally defines an operational isomorphism between spectral damping in molecular vibronic systems and neuromodulatory control in biological sensory systems. Without asserting causal continuity or physical identity across scales, we show that both domains instantiate the same class of output-selective…
M. Alexander Ardagh, Omar A. Abdelrahman, Paul Dauenhauer
Acceleration of catalytic transformation of molecules via heterogeneous materials occurs through design of active binding sites to optimally balance the requirements of all steps in a catalytic cycle. In accordance with the Sabatier principle, the characteristics of a single binding site are balanced between at least…
Siyu Liu, Kaitao Lin, Weiye Hu, Zhenzhao Yi + 3 more
'Jianghai Wo' 'Jianping Yao'] Abstract—We propose and implement a microwave photonic multi-mode injection-locked frequency divider (ILFD) with a wide frequency operational range based on an optoelectronic oscillator (OEO). In the OEO, a Mach-Zehnder modulator (MZM) and a photodetector (PD) are employed to construct a…
Temidayo O. Otunniyi, Hermanus C. Myburgh, Stefano Mariani
Realising a low-complexity Farrow channelisation algorithm for multi-standard receivers in software-defined radio is a challenging task. A Farrow filter operates best at low frequencies while its performance degrades towards the Nyquist region. This makes wideband channelisation in software-defined radio a challenging…
Authors not listed
This report compares various simulation and data analysis methods for free induction decay (FID) signals in Nuclear Magnetic Resonance (NMR) Spectroscopy. The methods discussed include discrete fast Fourier transformation (FFT), least squares fitting (LSF), short-time Fourier transformation (STFT), and wavelet…
Dimitris A. Barkas, George Ch. Ioannidis, Stavros D. Kaminaris, Constantinos S. Psomopoulos + 1 more
'Constantinos S. Psomopoulos' 'Fco Javier Rodríguez'] During the last few decades, the poor quality of produced electric power is a key factor that has affected the operation of critical electrical infrastructure such as high-voltage equipment. This type of equipment exhibits multiple different failures, which…