Lerkvaranyu, Somkiat

Preferred name

Alternative Name

Lerkvaranyu, S.

Main Affiliation

School of Engineering

somkiat.le@kmitl.ac.th

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The variation of critical frequency of E layer over Chumphon, Thailand
(2013-12-09)
Wongcharoen, Poramintra
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Kenpankho, Prasert
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Sepsirisuk, Kasemsuk
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Supnithi, Pornchai
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Noppanakeepong, Suthichai
In this research paper presents the observed critical frequency of E layer (foE) over Chumphon, Thailand which is located at nearly the magnetic equator (lat. 10.72° long. 99.37° dip. 3°) during September 2004 to August 2005. The foE is one of essential parameters in the International Reference Ionsphere (IRI) model. We investigate the variation of the observed foE by comparing to the Sun spot number, ionospheric index, and 10.7 cm. flux. Due to essentially of accurate IRI model can be used to applied in communication such as it may be implied tendency of phenomena in E layer effect on high frequency communication over Chumphon, Thailand. © 2013 IEEE.
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Wide-band CMOS precision rectifier circuit
(2008-12-01)
Kumngern, Montree
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Lerkvaranyu, Somkiat
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Dejhan, Kobchai
A wide-band precision CMOS rectifier, which is very suitable for integrated circuit implementation, is presented. The proposed circuit consists of a voltage-to-current converter, two precision rectifiers and four current-to-voltage converters that performs positive half-wave, negative half-wave, positive full-wave and a negative full-wave rectifications into a single circuit. The precision current-mode rectifier with operating in class-AB is employed to provide the high-frequency capability of the circuit. The circuit exhibits a very versatility, high operating frequency and good temperature stability The proposed configuration is very suitable for integrated circuit implementation both CMOS and bipolar technologies. The simulation results in CMOS technology demonstrate the performance of the proposed circuit. © 2008 IEEE.
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A Wien-type oscillator using ECCII
(2017-01-18)
Suksaibul, Pichai
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Lerkvaranyu, Somkiat
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Kumngern, Montree
This paper presents a new Wien-type oscillator using electronically tunable current conveyors (ECCII). Unlike previous Wien-type oscillators, the condition of oscillation of the proposed circuit can be controlled electronically using the current gain of ECCII. The structure is realized using grounded resistor which is easy for developing as a voltage-controlled oscillator. The condition and frequency of oscillations can be controlled orthogonally. PSPICE simulation results are given to confirm the presented theory.
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A square-wave generator using ECCII
(2017-07-02)
Kumngern, Montree
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Suksaibul, Pichai
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Lerkvaranyu, Somkiat
This paper presents a new square-wave generator using electronically tunable second-generation current conveyors (ECCII). The proposed circuit employs one ECCII, two resistors and one resistor. Unlike previous works, oscillating condition can be given by current gain of ECCII and the output frequency can be controlled by changing resistor. Both voltage and current signals can be obtained into a single topology. The proposed circuit is simulated using PSPICE simulators to confirm the workability of the circuit.
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M-QAM demodulation in an OFDM system with RBF neural network
(2004-12-01)
Lerkvaranyu, Somkiat
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Dejhan, Kobchai
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Miyanaga, Yoshikazu
This paper proposes a method which improves the M-QAM demodulation in the orthogonal frequency division multiplexing (OFDM). The OFDM has several advantages, i.e., the possibility of a simple equalization of the received signal. However, the disadvantages are also considered as the phase ambiguity due to intercarrier-interference (ICI) which causes the significant degradation on the performance of an OFDM system. The proposed method is a radial basis function (RBF) neural network which learns the characteristic of M-QAM signal constellation before reconstructing the correct signal constellation under noisy circumstances. The hybrid learning process is used to train the RBF network. The hidden layer is trained by the hard c means clustering. The supervised learning with given input-output pairs are used to train the output layer. This paper assumes an additive white Gaussian noise (AWGN) channel. The simulation results of the random symbol generations show that the probability of errors closes to ideal with the proposed method. OFDM, QAM demodulation, Self-organized clustering.
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Square/triangular wave generator using single bulk-driven FDCCII
(2019-07-01)
Torteanchai, Usa
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Manman, Somsak
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Kumngern, Montree
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Lerkvaranyu, Somkiat
This paper presents a new square/triangular wave generator based on ultra-low voltage fully differential second generation current conveyor (FDCCII). The circuit is composed base on Schmitt trigger and integrator circuits that employs one FDCCII, four resistors and one capacitor. The circuit can generate both square and triangular output waveforms into one topology. The performance of proposed circuit is confirmed using PSPICE simulations with a standard 0.18 \mum CMOS process and with a 0.5 V supply.
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Current-Mode Shadow Filter with Single-Input Multiple-Output Using Current-Controlled Current Conveyors with Controlled Current Gain
(2024-01-01)
Kumngern, Montree
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Khateb, Fabian
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Kulej, Tomasz
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Kyselak, Martin
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Lerkvaranyu, Somkiat
In this paper, a novel current-mode shadow filter employing current-controlled current conveyors (CCCIIs) with controlled current gains is presented. The CCCII-based current-mode shadow filters are resistorless and can offer a number of advantages such as circuit simplicity and electronic tuning capability. The proposed shadow filters offer five filtering functions, i.e., low-pass, high-pass, band-pass, band-stop, and all-pass functions, in the same topology. Furthermore, no component matching condition is required to realize all the transfer functions. The natural frequency and quality factor adjustment is possible by using the CCCII current gains without the need to use external amplifiers, all capacitors are grounded, and the filter terminals offer low-input and high-output impedance. To verify the functionality and feasibility of the new topologies, the proposed circuits were simulated using SPICE and the transistor model process parameters NR100N (NPN) and PR100N (PNP) from AT&T’s bipolar arrays ALA400-CBIC-R. The simulation results are consistent with the theory. The CCCII experimental setup was designed using commercially available 2N3904 (NPN) and 2N3906 (PNP) transistors with a supply voltage of ±2.5 V. The measurement results confirm the performance of the designed filters.
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An Ultralow-Power 0.5-V MI-OTA-Based Universal Filter for Efficient Low-Frequency Signal Processing
(2026-01-01)
Kulej, Tomasz
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Kumngern, Montree
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Khateb, Fabian
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Lerkvaranyu, Somkiat
This work introduces novel universal filters implemented using multiple-input operational transconductance amplifiers (MI-OTAs). The MI-OTA is specifically designed for a minimal 0.5-V supply, achieving nano-watt level power dissipation, which positions the design as highly viable for demanding ultralow-power systems. The architecture employs a subthreshold, multiple-input, bulk-driven MOS configuration. This design not only extends the operational input voltage range but concurrently ensures minimal voltage and power consumption. The primary filter topology utilizes five MI-OTAs and two grounded capacitors to concurrently deliver all five standard filtering responses—low-pass, high-pass, band-pass, band-stop, and all-pass filter—from a single, fixed circuit structure. By integrating a sixth MI-OTA, the architecture becomes reconfigurable for operation in both voltage-mode (VM) and transimpedance-mode (TIM). This versatility yields both non-inverting and inverting transfer functions for all five fundamental responses, resulting in a total of 20 distinct output functions. This multifunctionality and power efficiency make the proposed designs exceptionally well-suited for low-frequency applications, such as bio-signal processing and sophisticated sensor interfacing circuits. Furthermore, a key feature is that the filter's natural frequency is electronically tunable across all responses. The MI-OTA was designed and simulated in Cadence Virtuoso, utilizing the TSMC 65-nm (1P9M) CMOS process. The device occupies a modest silicon footprint of 125 μm × 92 μm. Simulation results confirm a power dissipation of 150 nW at a 177-Hz cutoff frequency under the 0.5-V supply. Post-layout simulations verified the expected circuit performance. Finally, experimental validation was conducted using a discrete-component MI-OTA-based circuit built with the LM13700, thereby confirming the filter's correct operation.
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Voltage/current-mode universal filter using single FDCCII
(2019-07-01)
Jongchanachavawat, Wirote
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Kumngern, Montree
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Lerkvaranyu, Somkiat
This paper presents a new voltage/current-mode universal filter using single fully differential second generation current conveyor (FDCCII). The topology can be realized both voltage and current-mode filters such as low-pass, band-pass, high-pass, band-stop and all-pass filtering functions without changing circuit topology. The circuit employs one FDCCII, two capacitors and two resistors. The performance of proposed circuit is confirmed using PSPICE simulations with a standard 0.35 \mum CMOS process.
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0.3 v Fully Differential Current Conveyor Using MIBD-DT MOST technique
(2022-01-01)
Kumngern, Montree
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Torteanchai, Usa
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Wongprommoon, Natapong
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Jongchanachavawat, Wirote
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Tooprakai, Siraphop
This paper presents a new fully differential second-generation current conveyor (FDCCII) using multiple-input bulk-driven dynamic threshold voltage MOS transistor (MIBD-DT MOST) technique. This FDCCII, the MOST techniques such as the multiple-input (MI), bulk-driven (BD) and dynamic threshold voltage (DT) have been used. The MIBD can be reduced the number of differential pair of FDCCII and the DT-MOST technique can be reduced the power supply requirement. Thus, the proposed FDCCII is capable to working with a supply voltage of 0.3 V and it consumes a 0.132 uW of power dissipation. The simulations were performed with SPICE program using the 0.18 um CMOS technology. To prove the workability of the new circuit, the proposed FDCCII has been used to realize universal filter.

Lerkvaranyu, Somkiat

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