Application of Taguchi signal to noise ratio design method to ZnO thin film CMOS SAW resonators

A systematic approach using Taguchi method is proposed for optimization of complementary metal oxide semiconductor microelectromechanical system surface acoustic wave (SAW) resonators. The aim of the present method is to enhance the performance of SAW devices in terms of electromechanical coupling coefficient while reducing the design and development cost. Controllable factors such as a number of transducers, N t , the distance between input and output transducers, L c , and the thickness of the piezoelectric materials, T c have been optimized. L 27 (3 13 ) orthogonal array was chosen to conduct 27 simulations with three level parameters. Time and cost efficient 2D finite element simulations were done using COMSOL Multiphysics TM for two-step analysis Eigen frequency and frequency domain analysis. The orthogonal array, signal to noise ratio, and analysis of variance (ANOVA) were calculated to determine the best settings of the design parameters. The maximum electromechanical coupling coefficient is achieved at the optimal condition of N t = 6; L c =1.6 μm; T c =2.5 μ m with increased performance by 4.68% for κ 2 and 9.62% for G 12 (f) compared to the initial conditions. The interaction between pairs of factors has also been investigated. The Taguchi method reveals that both N t and L c , and the interaction of N t × L c plays crucial roles in optimizing the electroacoustic conversion of the SAW devices. Hence, the experiment shows that the performance of the SAW device has been successfully optimized

Design and analysis of a boosted pierce oscillator using MEMS SAW resonators

This paper highlights the design and analysis of a pierce oscillator circuit for CMOS MEMS surface acoustic wave resonators. The boosted pierce topology using two, three-stage cascode amplifiers provides sufficient gain to counteract the high insertion losses of - 65 dB at 1.3 GHz of the SAW resonator. For accurate prediction of the oscillator’s performance before fabrication, circuit design utilized touchstone S2P measurement results of the MEMS SAW resonator, which provides better results compared to the conventional method of using equivalent circuit simulations. This circuit was designed using Silterra’s 0.13 lm CMOS process. It has low power consumption of 1.52 mW with high voltage swing 0.10–0.99 V. All simulations were conducted using Cadence Design Systems and results indicate that phase noise of 92.63 dBc at 1 MHz

Performance configuration of Raman-EDFA hybrid optical amplifier for WDM applications

A hybrid configuration of Raman amplifier and erbium-doped fiber amplifier (EDFA) is proposed to obtain a better performance in term of gain, noise figure and flat gain. It is based on the optimum parameter configuration of a singly-based Raman amplifier and EDFA. The best parameter for both amplification has been analyze in terms of its input signal power, pump power and their fiber length whereas the best erbium ion density has also been analyze in EDFA setup. All the parameters are varied to some values to get the optimum result. The simulation is done by using Optisystem 14.0 software. The hybrid amplifier consists of Raman amplifier with multi-pump power set up and bidirectional pump power of EDFA with the pump wavelength of 980 nm is designed and simulated in order to obtain higher gain and lower noise figure. From the simulation of the hybrid configuration, the optimum output has been achieved. The hybrid configurations exhibit the average gain of 46 dB and average noise figure of 3 dB. The flat gain obtained is between 1530 nm to 1600 nm which include C-Band and L-Band frequency with the gain bandwidth of 70 nm.

Material characterization of a doped triangular silicon nanowire using raman spectroscopy

A top-down silicon nanowire fabrication using a combination of optical lithography and orientation dependent etching (ODE) has been developed using a doped Silicon-on Insulator (SOI) as the starting substrate. The use of ODE etchant such as potassium hydroxide (KOH) and Tetra-Methyl Ammonium Hydroxide (TMAH) is known to create geometrical structures due to its anisotropic mechanism of etching. The SOI is doped with an n-type dopant (phosphorus) and the doped silicon nanowire is then characterized using Raman Spectroscopy. Due to the changes in the silicon structure, the result shows that the highly doped silicon nanowire has a wider Full Width Half Maximum (FWHM) as compared to the undoped silicon substrate

Ripeness assessment and quality control of mango gold susu using an e-nose system

In this paper, the development and implementation of an electronic nose (e-nose) system utilizing the MQ sensor series from MOS-type gas sensors to classify mango gold susu ripeness is presented. The system's performance was enhanced through machine learning techniques, including Principal Component Analysis (PCA) for data dimensionality reduction and Support Vector Machine (SVM) for classification. The SVM classifier demonstrated high accuracy, particularly in identifying unripe and overripe mangoes, with accuracy scores of 1.00 and 0.99, respectively. A comprehensive database of volatile organic compound (VOC) profiles was established, leading to a precise prediction model for assessing the different stages of ripeness based on the mango’s VOC profile

Dependence of preferred c-axis orientation on RF magnetron sputtering power for AZO/Si acoustic wave devices

We report the deposition of high quality c-axis oriented Aluminium doped Zinc Oxide (AZO) on silicon substrate for surface acoustic wave (SAW) applications. AZO thin film is prepared by Radio frequency magnetron sputtering method. Sputtering is a preferred method because it is able to perform deposition at low temperature, produce uniform thin film and possesses high deposition rates. In preserving the functionality of the device during post CMOS process, low deposition temperature is crucial. In order to obtain the preferred AZO structural properties with strong acoustoelectric interaction, we investigate the influence of RF power on c-axis preferred orientation of AZO/Si multilayer. The deposited thin films are characterized by X-Ray diffractometer and scanning electron microscopy (SEM). The crystal structures are evaluated in terms of c-axis lattice constant, d-spacing and crystallite size. It is observed that as RF power increases, the AZO film is predominantly oriented at c-axis (002) and achieved high crystalline quality. However, if the applied RF power is too high, the energized ions would impede the growth of high quality film. The optimum RF power was found to be at 250 W, at which the material exhibits hexagonal wurtzite-type lattice of ZnO structure, high crystallinity (lowest FWHM value) and crystallite size, and high deposition rate

Vibrational piezoelectric energy harvester’s performance using lead zirconate titanate versus lead-free potassium sodium niobate

Piezoelectric energy harvester (PEH) is considered as a robust power source, which can power electronic devices by scavenging small magnitudes of energy from ambient vibration. The fundamental advantage of PEH lies in the inherent ability of the piezoelectric material to generate electricity depending on the amount of vibration applied to the material. Although lead zirconate titanate (PZT) is the most common type of piezoelectric material used, the toxicity of PZT damages the environment and causes health issues, thus necessitates the need for the discovery of lead-free piezoelectric material. Hence, potassium sodium niobate (KNN) was chosen to eradicate the toxicity of the PZT material. In this paper, the performance of KNN energy harvester was compared with a commercial lead-based material using finite element modelling. Both harvesters showed a comparable output power of 0.104 mW for KNN and 0.115 mW for PZT, respectively. The recorded maximum output voltage of KNN was 0.952 V when resonated at 2097.7 Hz. KNN also rank among the best piezoelectric energy harvester compared to the commonly reported electromechanical coupling coefficient and figure of merit. The proposed KNN energy harvester provides a very promising solution to substitute lead-based energy harvester in the future

Finite element simulation of single Zinc Oxide nanorod for piezoelectric nanogenerator

The growing demand for sustainable and clean energy sources has motivated the development of wearable energy harvesters for portable and wearable electronic devices. However, the use of bulky and hazardous batteries poses challenges in terms of size, flexibility, and environmental impact. This paper addresses these challenges by presenting a 3D finite element simulation of single Zinc Oxide (ZnO) nanorod that has potential application as a wearable energy harvester. The effect of varying the aspect ratio (diameter/length) of ZnO nanorods toward the generated output voltage was investigated. The relationship between the variation of applied force to the output voltage and displacement of the vibration was also presented. The analysis results revealed that increasing the aspect ratio of the single ZnO nanorod led to higher generated output voltages. Similarly, applying higher forces resulted in increased voltage output. The optimum design of the single ZnO nanorod that has the highest output voltage is D=30nm L=9000nm force=500nN. The simulation results also demonstrated that the length and diameter of the nanorods influenced the generated piezoelectric potential

Single-mode fiber coated with zinc oxide (ZnO) nanorods for H2 gas sensor applications

A Hydrogen (H2) gas sensor was successfully developed using optical fiber coated with Zinc Oxide (ZnO) nanorods. The single-mode fiber (SMF) used as a sensing device has been prepared by etching the SMF fiber and coated with ZnO nanorods. The etching of the fiber was performed using hydrofluoric acid (HF) to enhance the evanescent field around the fiber core. The ZnO nanorods were prepared by hydrothermal method through seeding and growth solution technique. The diameter of cladding and core are 125 μm and 8 μm, respectively, before etching and goes down to 11μm after etching. Around 2 cm of ZnO nanorods were coated in the middle of the etched fiber. The sensing layer was characterized through Scanning Electron Microscopy (SEM), Energy Dispersive X-Ray (EDX) and X-Ray Diffraction (XRD) to verify the properties of ZnO. The developed sensor's response and recovery time were observed to be 7 min and 3 min, respectively, for a low concentration of 0.25% H2 gas. The aim of this study is to understand the gas sensing properties towards the spectral intensity variations in etched optical fiber coated with ZnO nanorods