This paper describes the first optical phase lock loop (OPLL) based on a photonic integrated circuit (PIC) fabricated using the generic foundry process and off-the-shelf electronic components. The PIC contains a DBR laser that can be... more
A spectrally filtered Optical Frequency Comb (OFC) laser is proposed as a versatile calibration source for astronomical spectrometers in the 1-2 μm spectral range. Such a source overcomes the limitations of current calibration lamps... more
The dispersion relation and mode amplitudes of oblique surface waves propagating on an acoustic double comb filter are obtained with a method based on the calculus of residues. We obtain a better agreement (below 480 Hz) between... more
Optical comb filter generation was proposed and experimentally demonstrated by using Fabry-Perot interferometer in micro cavity. The change of length of Fabry-Perot interferometer modifies the interference pattern with the adjusted length... more
This paper proposes a novel multiplierless comb compensation filter, which has the absolute passband deviation less than 0.1dB in the wide passband. The compensator consists of a cascade of two simple filter sections, both operating at a... more
In this paper, we present a method for separating voiced sounds from a composite signal. This method is mainly based on the separation by modified comb filter. This filter is keyed to the average values of the estimated pitch. This... more
In this paper, we propose a speech enhancement approach for a single-microphone system. The main idea is to apply a specific transformation on the speech signal depending on the voicing state of the signal. We apply a voiced/unvoiced... more
An analog topology is proposed to implement a comb filter for removal of power-line interference from various lowamplitude biomedical signals. In this proposed methodology, an n-number of all-pass filters (APFs) and an adder circuit are... more
It is shown that EEG visual evoked potentials elicited by repetitive stimuli in the range of 2 to 20 per second can be readily estimated in real time using a simple filtering approach. This measurement takes advantage of the fact that a... more
An analytical and experimental study of the pulsed ultrasonic comb filtering effect is presented in this work intending to provide a fundamental tool for data analysis and phenomenon understanding in pulsed ultrasonics. The basic types of... more
The dispersion relation and mode amplitudes of oblique surface waves propagating on an acoustic double comb filter are obtained with a method based on the calculus of residues. We obtain a better agreement (below 480 Hz) between... more
This paper presents new method for RF field amplitude and phase calibration in FLASH accelerator. Theold method for calibration had some disadvantages, which are absent in a new method. The concept is based ondetection and measurement of... more
A power-efficient clock/data distribution technique for the input registers of the polyphase comb decimation filter is presented. A general form of the proposed technique is developed with respect to the decimation factor. Both proposed... more
We study numerically an erbium doped figure eight fiber laser including a double bandpass opti cal filter for dual wavelength pulse generation. Simulations are performed for several values of the filter band width and wavelength... more
We demonstrate broadband comb-line generation from an integrated multiple quantum well InGaAsP/InP passively mode-locked laser (MLL) with a gain flattening filter (GFF) based on an asymmetric Mach-Zehnder interferometer. The intracavity... more
it te en nd dr ra a K Ku um ma ar r D Da as s D De ep pa ar rt tm me en nt t o of f E El le ec ct tr ro on ni ic cs s & & C Co om mm mu un ni ic ca at ti io on n E En ng gi in ne ee er ri in ng g N Na at ti io on na al l I In ns st ti it... more
We presented a compact and enduring multiwavelength Tm-doped fiber laser at 2 μm employing a microfiber knot resonator (MKR). The MKR, made by the flame-brushing technique, has a fiber diameter of 10 μm and a ring diameter of 150 μm. The... more
High order repetitive control application to a CD-player system van den Eerenbeemt, J.F. Award date: 2003 Link to publication Disclaimer This document contains a student thesis (bachelor's or master's), as authored by a student at... more
In this paper, FPGA implementation of comb filter required for hearing aids useful for hearing impaired people suffering from sensorineural hearing loss has been proposed. The difficulties in algorithm implementation on FPGA based... more
This paper presents a computationally efficient design of modified cosine-based decimation filters. One of the main contributions of this paper is the proposal of a multiplierless finite impulse response low-order linear-phase filter to... more
We have realized a first optical filter composed of optical delay lines and couplers that has a periodic response with respect to wavelength, whereas a conventional optical filter is known to have a periodic response to relative optical... more
Adaptive Rejection of Narrow Band Disturbance in Hard Disk Drives
Received: 4 February 2020 Accepted: 10 December 2020 The cascaded integrator comb (CIC) filters are characterized by coefficient less and reduced hardware requirement, which make them an economical finite impulse response (FIR) class in... more
This paper presents a novel two-stage comb decimator with the improved magnitude characteristic. Simple multiplierless corrector filters, which are designed using the frequency sampling and IFIR methods, are introduced. The proposed... more
Frequency comb may be virtually seen in the direct observation of the velocity selective optical pumping of the rubidium ground state hyperfine levels induced by a train of femtosecond pulses. The accumulation effects can be easily... more
Department of Signal Processing and Acoustics DAFx-09 presentation — September 4, 2009 — Slide 1 / 11 ... Spectral Delay Filters with Feedback and Time-Varying Coefficients Jussi Pekonen, Vesa Välimäki, Jonathan S. Abel and Julius O.... more
Multiwa¨elength lasers can be generated by adding a Fabry᎐Perot filter in the ring ca¨ity. Changing the¨oltage of the piezo-() electric transducer PZT in the F᎐P filter, one, two, or three wa¨elengths can be generated, respecti¨ely. The... more
We developed a simple seminumerical method to model, get design parameters, and estimate performance of side-polished microstructured optical fiber (SPMOF)-based devices. As an example, we analyze a SPMOF directional coupler and show good... more
Sensorineural hearing loss, caused by damage to the cochlea in the inner ear or to the auditory nerve, is associated with reduced dynamic range and increased spectral and temporal masking and results in degraded speech perception. For... more
This paper presents the passband-droop compensation of a modified non-recursive comb filter where the decimation factor is a power of two. The modified non-recursive comb filter is introduced to improve the alias reduction in the first... more
This paper presents an application of two-parameter robust repetitive control (TPRRC) in disk drive servo control, where the repeatable rrmout (RRO) and non-repeatable runout (NRRO) are rejected simultaneously. The repeatable disturbances... more
Filter is the most important element in digital signal processing. Infinite Impulse Response (IIR) filter is a digital filter. Based on FPGA different order of low pass IIR filters are designed. To design the different order of IIR... more
A power-efficient clock/data distribution technique for the input registers of the polyphase comb decimation filter is presented. A general form of the proposed technique is developed with respect to the decimation factor. Both proposed... more
This part of the paper presents TCAD simulations of the InAs/Si lateral nanowire (NW) tunnel FET (TFET) with the same geometry as the fabricated device discussed in the first part. In addition to band-to-band tunneling, trap-assisted... more
A characteristic of neurological signal processing is high levels of noise from sub-cellular ion channels up to whole-brain processes. In this paper, we propose a new model of electroencephalogram (EEG) background periodograms, based on a... more
it te en nd dr ra a K Ku um ma ar r D Da as s D De ep pa ar rt tm me en nt t o of f E El le ec ct tr ro on ni ic cs s & & C Co om mm mu un ni ic ca at ti io on n E En ng gi in ne ee er ri in ng g N Na at ti io on na al l I In ns st ti it... more
This decimation introduces the replicas of the main signal spectrum. If the signal is not properly filtered, the overlapping of the repeated replicas of the original spectrum, called aliasing, may occur. The aliasing may destroy the... more
To realize a broadband, large-line-spacing astro-comb, suitable for wavelength calibration of astrophysical spectrographs, from a narrowband, femtosecond laser frequency comb ("source-comb"), one must integrate the source-comb with three... more
A multi-GHz frequency comb (astrocomb) is typically realized by filtering modes of a sub-GHz frequency comb (source comb) in a Fabry-Pérot etalon, which can lead to ambiguities in determining which subset of source comb modes has been... more
A power-efficient clock/data distribution technique for the input registers of the polyphase comb decimation filter is presented. A general form of the proposed technique is developed with respect to the decimation factor. Both proposed... more
In this paper, tuneable comb filter using single-mode fiber (SMF)has been proposed and theoretically studied its capability of tuning the output spectral spacing continuously by using the birefringence property of polarization maintaining... more
This paper discusses the optimal H ∞ control synthesis via discrete Riccati equations for hard disk drives (HDDs) with an irregular sampling rate. A HDD servo system with an irregular sampling rate, caused by missing position error signal... more
The Moog ladder filter, which consists of four cascaded first-order ladder stages in a feedback loop, falls within the class of devices that have attracted greatest interest in virtual analog research. On one hand, this work confirms that... more