Jaikla, Winai

Preferred name

Jaikla, Winai

Alternative Name

Jaikla, W.

Main Affiliation

School of Industrial Education and Technology

winai.ja@kmitl.ac.th

Now showing 1 - 10 of 18

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Comparison of Two Solutions of Quadrature Oscillators With Linear Control of Frequency of Oscillation Employing Modern Commercially Available Devices
(2015-11-23)
Sotner, Roman
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Jerabek, Jan
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Langhammer, Lukas
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Polak, Josef
;
Herencsar, Norbert
This paper proposes two circuits of frequency-controlled oscillators, whose structures are based only on simple commercially available active elements with minimum number of terminals, in particular, the differential voltage buffer, controllable voltage amplifier and electronically controllable current conveyor. Two methods for achieving linear control (tuning) of frequency of oscillations (FO) are discussed. The first method employs a simple structure. However, the generated signal level (amplitude) depends on the tuning process. This is a drawback of this method. The second method solves this drawback completely, and the generated signals have constant amplitudes during the tuning of FO. The expected behavior is confirmed by laboratory experiments utilizing commercially available high-speed active elements (current- and voltage-mode multipliers, video difference amplifier). Operational range was tested from frequencies of hundreds of kHz up to frequencies of tens of MHz.
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Design of Phase-Locked Loop Using Special Analog Multipliers and Voltage Buffers: Demodulation of Transposed Signals from Sensors
(2024-01-01)
Svoboda, Marek
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Sotner, Roman
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Polak, Ladislav
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Jerabek, Jan
;
Jaikla, Winai
Phase-locked loops (PLLs) are versatile electronic circuits that, among others, are used in various sensor applications (e.g., medical) for their ability to generate stable and precise clock signals. This article introduces a novel PLL-based frequency demodulation system designed for processing of very slow signals, ranging from a few Hz to several hundreds of Hz, with amplitudes in the order of several hundreds of millivolts. The system incorporates specialized analog multipliers tailored for essential PLL components, including the voltage-controlled oscillator, phase detector, loop filter with variable DC offset, and baseband filter, all optimized for the purpose of frequency demodulation. These multipliers were fabricated using the TSMC 0.18~μ m, 1.8 V CMOS process. The primary design objectives are simplicity, reduced complexity, low power consumption (merely 15 mW), and versatility for applications in sensing engineering. To validate the functionality of the proposed PLL system under practical conditions, we present an example of electrocardiogram and photoplethysmogram signal demodulation, demonstrating its operational performance.
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Compact active analog device for novel applications useful for sensing and measurement
(2024-08-01)
Sotner, Roman
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Jerabek, Jan
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Polak, Ladislav
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Jaikla, Winai
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Andriukaitis, Darius
The presented research introduces a novel approach to modern modular active device and provides various practical application examples tailored for industrial sensing readouts. Straightforward implementation of single active device-based topologies in frequency bands from kHz up to MHz is presented. These applications include: an electronically linearly tunable special band-pass filter that can be easily modified into a voltage-controlled oscillator, a two-port quadratic transformer, an amplitude modulator, and an equalization circuit (which serves as a fractional-order differentiator and integrator). These circuits benefit from high-impedance voltage input and low-impedance output (easily matched to 50 Ω), high processed signal levels (often reaching hundreds of mV), and simplified topologies without redundant passive elements. These features are especially valuable in tunable and configurable solutions for modern communication, sensing, audio, and consumer electronic systems, as well as in modeling various physical and biological systems. The experiments have been provided by simulations and measurements using device VCA824.
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Exponentially tunable voltage controlled quadrature oscillator
(2017-10-19)
Sotner, Roman
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Jerabek, Jan
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Petrzela, Jiri
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Domansky, Ondrej
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Jaikla, Winai
This paper deals with appropriate method of tunability extension in quadrature oscillators. Exponential dependence of frequency of oscillations on DC control voltage is created in lossless integrators by utilization of two exponentially controlled variable gain amplifiers and diamond transistors. Proposed solution maintains all beneficial features (especially independent levels of output waveforms on tuning process) of the oscillator concept employing two lossless integrators in the single loop and electronically controllable negative resistor serving for adjusting of condition of oscillations. PSpice verifications based on simulations of macromodels of used active devices confirmed doubled tunability range in comparison to standard linear control of frequency obtained for the same change of DC driving voltage.
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Design of Constant Phase Elements for Adjustable Pseudocapacitance by a Single Driving Voltage Using Integrated Unipolar Transistor Fields
(2026-01-01)
Sotner, Roman
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Litovska, Anna
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Polak, Ladislav
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Jerabek, Jan
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Kledrowetz, Vilem
This paper presents the design of a passive fractional-order element with tunable pseudocapacitance, enabling adaptable circuit behavior without additional power consumption. This is an important feature for modelling and characterization in natural systems, as well as in the field of electrical and electronic engineering, particularly for the design of instrumentation and sensing systems. The proposed topologies are based on integrated unipolar transistor arrays. Two implementations are demonstrated, with fractional orders of 0.22 and 0.5, offering pseudocapacitance adjustment ranges from 65 to 1 670 mikroF/s^0.78 and from 6.7 to 51 mikroF/s^0.5, respectively. Tuning is achieved through a DC bias voltage ranging from 0.8 to 10 V. The devices operate across nearly two decades of frequency, from approximately 100 Hz to 200 kHz, and support signal amplitudes in the hundreds of millivolts. Two application examples highlight their potential: electronic tuning of the center frequency in a fractional-order band-pass filter, and adjustment of the oscillation frequency in a fractional-order oscillator with a fixed 22.5 degrees phase shift between output waves. All concepts and results are experimentally validated in the laboratory.
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Behavioral model for Z-copy Voltage Controlled Current Follower Differential Input Transconductance Amplifier and its features
(2015-10-09)
Jerabek, Jan
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Sotner, Roman
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Herencsar, Norbert
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Jaikla, Winai
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Vrba, Kamil
This contribution introduces behavioral model of multi-terminal active device providing electronically adjustable control of its parameters so-called Z-copy Voltage Controlled Current Follower Differential Input Transconductance Amplifier (ZC-VCCFDITA). Behavioral model is based on elements available in standard PSpice libraries in order to show that modeling of elements, blocks and sub-blocks representing specified functions can be easy. Furthermore, using of commercially available devices allows experimental test without expensive on-chip implementation. The model allows electronic control of intrinsic current input resistance of the current input terminal and transconductance control by DC voltages. Features of the model are verified by simulation.
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Special Transfer Section for Selective Rejecting and Amplification of Bands in Equalization
(2024-01-01)
Sotner, Roman
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Svoboda, Marek
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Semenov, Dmitrii
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Polak, Ladislav
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Jerabek, Jan
This paper introduces a novel and simple filtering topology for band-reject (notch) and inverse band-reject applications, utilizing two voltage-adjustable operational transconductance amplifiers. The utilization of these active devices enables the implementation of identical topologies for both band-reject and inverse band-reject transfer functions. The resulting responses are harnessed for the cascade synthesis of a specialized comb filter, capable of amplification or attenuating/rejecting specific bands shown on three sub-bands. Both the design of individual sections and the entire cascade have been experimentally verified using active devices manufactured in the TSMC 180 nm CMOS process. Measurements conducted over a range from 10 Hz to 100 kHz demonstrate the importance of the selective filtering, which is significant for various applications, particularly in acoustic, vibration, and magnetic sensing readouts. The example of peaking suppression in magnitude response of emulated environment (acoustic coupling of piezo and microphone) is shown.
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Integer- And fractional-order VCO using non-inertial amplitude stabilization and modern active elements
(2020-04-28)
Sotner, Roman
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Petrzela, Jiri
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Jerabek, Jan
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Langhammer, Lukas
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Polak, Josef
This paper introduces design of the linearly tunable quadrature voltage-controlled oscillator (VCO) using modern off-the-shelf active elements suitable for the design of electronically adjustable applications. The simplified topology was achieved using non-inertial stabilization of amplitude. It allows targeting adjustability of the oscillation frequency only into lossless integrator part of the topology. This arrangement simplifies the design and the tenability also. Derived symbolical expressions indicate that gain adjustment of used amplifiers (that are still in single path) does not influence amplitude and phase shift ratio of generated waveforms, which is a beneficial feature. The performances of the circuit are tested experimentally in band of units of MHz and results confirmed expected behavior. Initial study of the oscillator with fractional-order capacitors is presented and discussed. Results are supported by laboratory measurements.
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Readout for simple and precise analog acoustic impact initialization
(2021-12-01)
Sotner, Roman
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Polak, Ladislav
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Jerabek, Jan
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Lahiri, Abhirup
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Jaikla, Winai
An economic concept of acoustic shock wave sensing readout system for simple computer processing is introduced in this work. Its application can be found in precise initialization of the stopwatch from the starter sound, handclap or gun in competitive sport races but also in many other places. The proposed device consists of several low-cost commercially available components and it is powered by a 9 V battery. The proposed device reliably reacts on incoming acoustic shock wave by generation of explicit impulse having controllable duration. It significantly overcomes basic implementations using only a microphone and amplifier (generating parasitic burst instead of defined and distinct impulse) or systems allowing a limited number of adjustable features (gain and/or threshold of the comparator—our concept offers the adjustment of gain, cut-off frequency, threshold level and time duration of active state). In comparison with standard methods, the proposed approach simplifies and makes sensing device less expensive and universal for any powder-based starting gun (without necessity to adapt starting gun). The proposed device, among others, has the following features: impulse duration can be controlled from hundreds of μs up to 2.3 s, the gain range of linear part of processing from 6 to 40 dB and open-collector output compatible with 5 V TTL or 3.3 V CMOS logic. The initialization has been tested in the range from tens of centimeters up to four meters. In order to highlight the important spectral components, the spectral character of the signal can be optimally reduced by a low-pass filter. The quiescent power consumption of the designed simple analog circuit reaches 90 mW. Several use cases, response of the designed system on gunshot signature, talking, hand-clapping and hit on the sensing microphone, are studied and compared to each other. Simulation and experimental results confirm functionality of the realized system.
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A Single Parameter Voltage Adjustable Immittance Topology for Integer- And Fractional-Order Design Using Modular Active CMOS Devices
(2021-01-01)
Sotner, Roman
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Jerabek, Jan
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Polak, Ladislav
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Prokop, Roman
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Jaikla, Winai
A simple single parameter adjustable immittance concept designed with modular active devices, fabricated in I3T $25~0.35~\mu \text{m}$ 3.3 V CMOS process of ON Semiconductor, is introduced. The proposed devices employ an integer-order capacitor and specifically designed fractional-order capacitors (sometimes called constant phase elements). The proposed active topology consists of two simple active elements, namely a linearly voltage adjustable operational transconductance amplifier and a voltage differencing unity gain voltage follower/buffer, and only two passive elements, i.e. redundancy is minimized. The designed topology offers generation of an adjustable immittance having both the capacitive and inductive character. The importance of the order as well as the value of the pseudo-capacitance for design and analyzes are shown, including all important parasitic features for estimation of expected operational bandwidth which have to be considered in the design. The operational bandwidth is determined by high values of approximants of fractional-order capacities (225, 56 and $8.8~\mu \text{F}$ /seĉ1- $\alpha $ , where $\alpha $ represents the order equal to 0.25, 0.5 and 0.75, respectively). These parameters result into ranges between tens of Hz and units-tens of kHz. The adjustability of the transconductance from 70 to $700~\mu \text{S}$ by the driving voltage between 0.05 and 0.5 V offers approximately one decade change of equivalent capacitance and inductance. Laboratory-based experiments done with a fabricated prototype confirmed the theoretical presumptions.

Jaikla, Winai

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