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We demonstrated the enhanced terahertz transmission through superconducting NbN subw ave length hole arrays. The transmission peak value and frequency exhibit thermal tuning behaviors, which can be attributed to the temperature-dependent complex permittivity of superconducting film. The microscopic hybrid wave model was adopted to analyze the role of surface waves in the enhanced transmission theoretically...
Aiming at the problem of inefficiency, low degree of automation in high voltage insulator detection, an auto detection system for insulator inspection robot was designed. Step motor was adopted as the drive for robot moving joints, FPGA was adopted as main control unit for step motor control, signal acquisition and wireless communication control. The man-machine interface was programmed by LabVIEW...
Short-range wireless terahertz (THz) communication and ultrafast THz interconnects require switches and modulators. Here, we experimentally show voltage-bias superconducting (SC) niobium nitride (NbN) metamaterial to realize a switch. The obtained maximum transmission coefficient at 0.507 THz is up to 0.98 and it drops to 0.19 when the applied voltage is only increased to 0.9 V. A relative transmittance...
Accurately measurement and monitor on methane gas concentration is an urgent issue to be solved in the purpose of safety and process control in homes, industries and mines. A new room temperature supra-molecular cryptophane A (CrypA)-coated Love wave based sensor incorporating a waveguide structure of SiO2/36° YX LiTaO3 was presented in this contribution for sensing methane (CH4), which exhibits some...
Recently, metamaterial in the terahertz (THz) region has become an attractive field as a novel approach to control and manipulate the electromagnetic waves. In this papaer, we report our recent development of nonlinear response and ultrafast dynamics from superconducting metamaterials at THz region measured by intense THz pump THz probe system. Both low temperature and high temperature superconducting...
We demonstrate a high-sensitive and multi-frequency THz measurement on the biomolecules based on a flexible metamaterial. The sensitivity of our proposed biosensor is finally achieved to be around 0.132 GHz/nm that is much higher than other reported results. The tumor molecules are coated on the metamaterial, and a very large frequency shift is observed, which implies its application in disease detection.
A new ion source based on modulated pulse power (MPP) magnetron sputtering (MSP) was developed and demonstrated for cluster production. By employing MPP-MSP, both silver and silicon cluster beams were produced and analyzed by a quadrupole mass spectrometer. It is found that the maximum intensity of silver cluster anions reaches 500 pA, which is considerably higher than that with a conventional DC-MSP...
A novel strategy has been proposed to implement high-performance ultra flexible RF resonators operated in the pseudo-Lamb wave modes. By integrating piezoelectric thin film (ZnO and AlN) with flexible polyimide (PI) substrate and using surface interdigital electrodes to excite acoustic waves, flexible RF resonators have been fabricated. Two-dimensional finite element analysis has been performed to...
The measurements for breakdown voltages have been made with point-plane electrodes for high-pressure carbon dioxide up to supercritical conditions at different temperatures. The breakdown voltages depend on electrode gap, temperature and pressure of gas while preserving the intrinsic nonlinear combination of these characteristics. Artificial neural network was used to model the complex nonlinear relationship...
This paper investigates the implementation of a least squares estimation of varactor capacitance values across a wafer for reasons of characterizing thin-film ferroelectric Ba0.6Sr0.4TiO3, barium strontium titanate (BST). The varactor design utilized for this characterization as well as an equivalent schematic representation of the device used will be presented. Comparisons between the estimated thin-film...
The main objective for this research is to develop an antenna that can shift its frequency over a broadband. A coplanar waveguide (CPW) antenna was designed with the center conductor of the CPW transmission line connected to a bowtie patch. The size of the antenna is 6mm × 6 mm. The antenna is tuned with a barium strontium titanate (BST) thin film varactor which can tune the device from 5.75 GHz to...
This paper presents a Space-Vector Modulated (SVM) Direct-Torque-Control (DTC) scheme for a direct-drive permanent magnet synchronous generator (PMSG) and a gird converter for wind energy without any position sensor. Direct control of the rotating velocity and amplitude of the stator flux vector allows very fast torque response of the PMSG according to the generator speed. Fixed switching frequency...
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