Sooksood, Kriangkrai
Loading...
Preferred name
Sooksood, Kriangkrai
Alternative Name
Sooksood, K.
Main Affiliation
Email
kriangkrai.so@kmitl.ac.th
7 results
Now showing 1 - 7 of 7
- Some of the metrics are blocked by yourconsent settings
Item type:Publication, A High-Q Floating Active Inductor Based VCO for L-Band and Lower C-Band Applications in 180 nm CMOS Technology(2023-10-01); Mohapatra, Sushanta KumarThis paper presents a low power, wide-tuned Inductor-capacitor (LC) voltage-controlled oscillator (VCO). A floating active inductor (FAI) with a high-quality factor (Q) is used in the VCO design. The FAI is designed with a cascode transistor pair and a cross-coupled transistor pair to achieve a high Q value of up to 3290. The inductance value of the FAI ranges from 12.5 nH to 256.2 nH. The VCO has 164.8% of oscillation frequency tuning, from 235 MHz to 2.83 GHz with a phase noise of −85.3 dBc/Hz to −102.4 dBc/Hz at 1 MHz offset frequency. The FAI and VCO have 17.1 × 18 µm<sup>2</sup> and 58.6 × 64.6 µm<sup>2</sup> silicon area respectively. The power consumption ranges from 6.8 mW to 8.62 mW within the frequency tuning range. The FAI and VCO are designed in UMC 0.18 µm mixed-mode CMOS technology. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Flexible Biphasic Functional Electrical Stimulator for Children with Cerebral Palsy(2021-08-27) - Some of the metrics are blocked by yourconsent settings
Item type:Publication, A thz metamaterial absorber with multiple polarization: Insensitive, sensitive, and tunable(2021-01-01); Mohapatra, Sushanta KumarTerahertz (THz) absorbers are gaining interest in many applications. In this paper, we present the design and simulation of a multiband metama-terial absorber (MMA) with combined polarization properties and prominent absorption at 2.2 THz and 3.9 THz. The MMA comprises two square split-ring resonators and one square ring resonator placed on top of a polyimide dielectric spacer, offering multiband absorption characteristics with maximum absorptivity of 93.18% and 96.09%, respectively. The most protruding feature of this design is that it displays multiple polarization characteristics, including insensitivity, sensitivity, and tunability, even though the structure is similar to those of conventional absorbers. Firstly, the distinctly visible absorption spectra at 1.8 THz, gradually diminishes with an increase in polarization angle and then completely vanishes for TM polarization. Secondly, the prominent band at 2.2 THz is insensitive to changes in polarization of the incident wave, whereas, at 3.9 THz, the absorption band displays polarization tunability characteristics. Due to the multiple characteristics displayed by the structure, this MMA can be simultaneously used for several applications in the terahertz frequency regime such as imaging, terahertz spectroscopy, sensing, and stealth technology. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Multichannel Microstimulating SoC(2022-01-01); Ortmanns, MauritsIn recent years, limited research was focused on designing a multichannel microstimulator that could demonstrate high flexibility in terms of pulse parameters, waveshapes, stimulation strategy, number of electrodes, high-voltage compliance, and variety of charge-balancing techniques to optimize the use of an implant chip for various implementations, changing operating conditions, or research on stimulation efficiency. The reason for this is that designing a highly flexible multichannel stimulator that could fulfill all the different neural applications while concurrently maintaining low power and area consumptions is not a trivial task. Normally, there is a trade-off between high flexibility and hardware complexity. For neural applications, including neuromuscular, cochlear implant, and deep brain stimulators, which require a small number of electrodes, high flexibility of waveform pattern at each stimulation site is not an issue. However, especially for a large number of electrodes, such as a retinal implant, having high flexibility in the waveform pattern is not easy to implement. Therefore, this chapter presents an overview of design and implementation of flexible multichannel microstimulator in system on chip (SoC). Firstly, the importance of having high flexibility in neural stimulator application and the trade-off between high flexibility and hardware complexity are discussed. Secondly, the state of the art of flexible waveform generation, charge-balancing techniques for safe stimulation, and power management requirements in multichannel microstimulators are reviewed. Thereafter, the examples of overall design architecture, stimulation protocols, flexible stimulation, and functionality for a multichannel epiretinal stimulator ASIC with 1024 electrodes are provided. In addition, an area- and power-efficient stimulator front-end circuit which covers the HV current driver, compliance monitor, and several types of charge-balancing techniques are further elucidated. Finally, a power management circuit with closed-loop power control and dynamic supply adaptation for multichannel epiretinal stimulator is explained in detail. A 16-channel epiretinal microstimulator has been developed and successfully tested in a 0.35 µm AMS HVCMOS technology. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, A Highly Compliant Current Driver for Electrical Stimulator with Compliance Monitor and Digital Controlled Offset Regulation Charge Balancing(2020-03-01); Noorsal, EmiliaA CMOS current driver for electrical stimulator in 0.35μm HVCMOS is presented in this paper. It is based on the regulated cascode current mirror in deep triode region. This driver requires approximately 500mV overdrive voltage over the current of 4μA to 1mA whereas maintaining output impedance higher than 10MΩ. The proposed topology also comes with the possibility to monitor the compliance voltage which is useful for the power-efficient adaptive supply voltage stimulation. Besides, the offset regulation active charge balancing is implemented using digitally controlled additional current sources. It is verified in vitro using a platinum black electrode in saline solution. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Performance of Smart Antenna Under Different Fading Conditions(2022-05-01); Mohapatra, Sushanta KumarOptimizing the current distribution of an evenly spaced antenna array has shown to be an efficient approach for reducing side lobe levels. In this article, the Tchebyscheff distribution-based antenna array synthesis approach is combined with an adaptive signal processing algorithm for beamforming and side lobe level reduction in smart antennas in various fading situations. The performance of smart antennas in uniformly spaced linear, planar, circular, and semi-circular arrays are evaluated. The presence of Rayleigh and Rician channels is examined in the network. The least mean square (LMS) and normalised least mean square (NLMS) algorithms are applied as adaptive algorithms. In fading environments, the NLMS algorithm with Tchebyscheff distribution outperforms than the LMS algorithm with Tchebyscheff distribution, with a side lobe level decrease of 11.23 dB. The lowest side lobe achieved with the NLMS algorithm with Tchebyscheff distribution is − 45.59 dB for uniform planar array. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, An RHCP and LHCP polarization reconfigurable microstrip antenna for ISM band smart city applications(2022-08-01); Mohapatra, Sushanta KumarIn this article, a microstrip antenna having circular polarization switching capability is presented. This antenna consists of a circular-shaped radiating patch with a single co-axial probe feed line. The polarization reconfigurability is achieved by introducing four symmetrical U-shaped slots and silicon PIN diodes on the radiating patch. A prototype of the design is fabricated on an FR-4 substrate with overall dimension of 70 × 70 × 1.6 mm to verify the performances. The measured results of the antenna exhibit an impedance bandwidth (S 11 < -10 dB) of 5% in the frequency range of 2.37-2.49 GHz. The maximum gain of the antenna is found to be 2.99 dBic at 2.43 GHz. The antenna shows stable radiation performances at 2.4 GHz with 4.1% of 3-dB axial ratio bandwidth, and more than 105° of 3-dB axial ratio beamwidth for both right-hand circular polarization and left -hand circular polarization which make it suitable for ISM band Smart city applications.