Chaichana, Amornchai
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Chaichana, Amornchai
Alternative Name
Chaichana, Amonchai
Chaichana, Amornchia
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Email
amornchai.ch@kmitl.ac.th
38 results
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Item type:Publication, Single commercially available ic-based electronically controllable voltage-mode first-order multifunction filter with complete standard functions and low output impedance(2021-11-01); ; - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Amplitude controllable current-mode first order allpass filter including minimum component count circuits(2015-10-09); ; - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Voltage-Mode First-order Multifunction Filter with Electronic Controllability Using VDDDA(2025-01-01); ; This study presents the design of a three-input single-output voltage-mode first-order multifunction filter. The proposed filter comprises a single VDDDA as the active component, one grounded capacitor, and two resistors. The output voltage node has low impedance. The proposed filter provides three responses consisting of a low-pass (LP), a highpass (HP), and an all-pass (AP) by setting the voltage signal at the input voltage. The natural frequency (f<inf>0</inf>) and phase response are electronically controlled by the bias current (I<inf>B</inf>). This flexibility allows for precise tuning of the filter characteristics to meet specific application requirements. The passband gain of LP and HP filters can be adjusted using resistors R<inf>1</inf> and R<inf>2</inf> without affecting the f<inf>0</inf> or requiring an additional amplifier. The simulation and experimental results validate the functionality of the proposed filter as anticipated theoretically. This reliability is crucial for communications and signal processing applications, where accurate signal representation is paramount. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, One input voltage and three output voltage universal biquad filters with orthogonal tune of frequency and bandwidth(2021-08-01); ; ; This research paper contributes the one input three output voltage mode universal biquad filters with linear and electronic control of the natural frequency (ω0), using two commercially available ICs, LT1228s as active device with two grounded capacitors, five resistors. The presented universal biquad filters can simultaneously provide three voltage-mode filtering functions, low-pass (LP), high-pass (HP) and band-pass (BP) without changing the circuit architecture. Furthermore, the first presented biquad filter provides low impedance at HP, BP voltage output nodes and LP, BP output voltage nodes are low impedance for the second proposed filter which is easy cascade ability with other voltage mode circuits without the employment of buffer circuits. The quality factor (Q) of both proposed filters is orthogonally adjusted from the passband voltage gain and ω0. The proposed filters are simulated and experimented with commercially accessible ICs, LT1228. The simulated and experimental results demonstrate the filtering performances. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Real-time GPS receiver bias estimation(2021-09-01); ; ; ; Hozumi, KornyanatIn this paper, we present the new method for real-time GPS receiver bias estimation by using Lagrange interpolation, which is also compared to the two current methods, polynomial and minimization of standard deviation. The estimated method is proposed to reduce the complexity and time of the GPS receiver bias estimation. Lagrange interpolation is the method to find the derivatives and integrals of discrete functions in GPS receiver bias data. The test site is located on Chumphon station, Thailand. The test period of data method is during the year 2004–2019. In the quiet and disturbed days, the polynomial method gives the highest value of the GPS receiver bias at −5.75 ns and −4.25 ns, respectively, but the Lagrange interpolation shows the lowest value of GPS receiver bias at −6.85 ns and −5.25 ns, in order. The results and comparisons among the polynomial GPS receiver bias method, the minimization of standard deviation of GPS receiver bias method, and Lagrange interpolation method show that the calculated time for Lagrange interpolation is shorter compared to other methods and it can be given more time points for finding GPS receiver biases than others. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Electronically tunable versatile current-mode MISO universal filter including minimum component count circuits(2014-01-01); ; An analog second order current-mode filter is described in this paper. The proposed filter uses only a single active building block, namely current following cascaded transconductance amplifier with two grounded capacitors which is attractive for monolithic chip implementation. The circuit has four inputs and single output currents. Five standard functions, namely low-pass, high-pass, band-pass, band-reject and all-pass functions, are given. The natural pole frequency and quality factor can be tuned electronically via the input bias current. The inverting-type input current signal is not required for realization of all-pass function. High output impedance is achieved which is convenient to cascade in current-mode circuit. The PSPICE simulation results are depicted. The given results agree well with the theoretical anticipation. © 2014 IEEE. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Synthesis of electronically tunable multifunction biquad filter using voltage differencing differential input buffered amplifiers(2025-02-01); ; ; Biquad filters are commonly used in analog circuits for various purposes in signal processing and communication applications. We synthesize an analog active biquad filter with five types of voltage-mode filtering functions. The filter is synthesized using a parallel passive resistor-inductor-capacitor (RLC) network and unity-gain voltage differencing amplifier. A voltage differencing differential input buffered amplifier (VD-DIBA) is the main active component, and the biquad filter has a three-input single-output (TISO) topology. By replacing the passive inductor and resistor with VD-DIBA-based inductance and resistance simulators with a subtractor, the TISO voltage-mode versatile filter is obtained from two VD-DIBAs, one resistor, and two capacitors connected to the ground. The proposed filter can provide five types of voltage-mode filtering functions: inverting bandpass and lowpass responses as well as noninverting band-stop, high-pass, and all-pass responses. The all-pass filter requires no additional active components. The three input voltage nodes have high impedance, and a low-impedance output voltage node facilitates cascade connections without using additional voltage buffers. In addition, the natural frequency and quality factor can be electronically tuned. The quality factor is controlled without disturbing the passband gain and natural frequency. The proposed filter is simulated and verified experimentally in the Personal Simulation Program with Integrated Circuit Emphasis (PSPICE) and through laboratory tests employing VD-DIBAs implemented using commercially available components.4 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Single Active Element Based Electronically Controllable Capacitance Multiplier(2022-07-15); ; ; The realization of capacitance multiplier using the versatile active building block, namely voltage differencing differential difference amplifier (VDDDA) is presented in this paper. The realized capacitance multiplier is very simple consisting of one VDDDA, one MOS resistor (RM) and one grounded capacitor which is attractive for integration. The multiplication factor (KC) of the realized circuit can be electronically controlled via the bias current (IB) and control voltage (VC) without the need of any matching condition of active and passive element. Moreover, the multiplication factor can be adjusted to be more or less than one. The performances of the presented capacitance multiplier are verified through Pspice simulation using CMOS VDDDA in 0.18μm TSMC technology with ±0.9V power supplies. The multiplication factor is designed to be KC=2 by choosing VC=0.85V, IB=50μA and C=30 pF. The simulated multiplication factor is around 1.98. The simulated operational frequency range is around three decades (6.16 kHz-8.91MHz). The performances of the proposed circuit are also verified by the experiment using VDDDA implemented from the commercial ICs, AD830 and LM13700 with ±5V power supplies. The experiment is conducted under the same multiplication factor (KC=2) as the simulation by choosing RM=0.27 kω (1% passive resistor), IB=96.2μA and C=1nF. The experimental multiplication factor is around 2.06. The experimental operational frequency range is around three decades (1kHz-1.25MHz). By adjusting the bias current from 17.67μA to 400 μA, the experimental multiplication factor is controllable from 11.47 to 0.48. The percent deviation of the theoretical and experimental multiplication factor is lower than 5% when the value of bias current is greater than 39μA. These deviations stem from the effect of the parasitic capacitance and resistance in VDDDA. Moreover, the application example of the presented capacitance multiplier as the sinusoidal oscillator is presented. The performances of the presented oscillator verified via the experiment are well consistent with theoretical anticipation.2 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Current-mode MISO filter using CCCDTAs and grounded capacitors(2015-07-01); ; This paper presents the current-mode multi-input single-output (MISO) biquadratic filter using current-controlled current differencing tranconductance amplifier (CCCDTA) as an active building block. The proposed circuit comprises three CCCDTAs and two grounded capacitors performing completely standard functions: low-pass, high-pass, band-pass, bandreject and all-pass functions and does not require double input current signals as well as inverting input currents. The pole frequency and quality factor of the proposed circuit can be adjusted electronically/independently via dc bias currents. In addition, the filter circuit has low-input and high-output impedance which facilitates easy connecting for current-mode circuit. The proposed circuit uses all grounded capacitors which is very suitable to further develop into an integrated circuit and without requiring any matching condition. Moreover, the active and passive sensitivities are low. The PSPICE simulation results are included to show the workability of the proposed circuit.1 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Control system technology of higher educational community traffic in Bangkok metropolitan(2017-07-01); The traffic network designed for the communities plan around higher education service areas in Bangkok and vicinity aimed to 1) study the traffic flow in the communities plan around the higher education service areas in Bangkok and vicinity, 2) study the appropriate information used to plan the traffic routes for the particular community's plan, and 3) provide control system of guideline for information needed for the traffic routes planning for the certain community's plan. The data was collected from 400 samples who were regular commuters in the certain area around the higher education service areas in Bangkok and vicinity through sets of questionnaires. Then, the data was analyzed based on the research methodology. According to the result, the researcher found that the city commuting network affecting the accessibility of each area should provide sufficient convenience for the commuting demand and it should be able to connect to other networks as well. Moreover, the traffic of the communities around the higher education service areas in Bangkok and vicinity must be easily understood, accessible, and each route must be used equally.1