Dielectric Material Characterization in the Frequency Range 68 - 92 GHz

2018 ◽  
Author(s):  
I. Alawneh ◽  
J. Barowski ◽  
I. Rolfes
Keyword(s):  
Material Characterization ◽  
Dielectric Material ◽  
Frequency Range

scholarly journals A hybrid broadband metalens operating at ultraviolet frequencies

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Farhan Ali ◽  
Serap Aksu
Keyword(s):  
Dielectric Material ◽  
Berry Phase ◽  
Uv Light ◽  
Fdtd Method ◽  
Numerical Aperture ◽  
Limited Range ◽  
Unit Cell ◽  
Dielectric Constants ◽  
Phase Method ◽  
Frequency Range

AbstractThe investigation on metalenses have been rapidly developing, aiming to bring compact optical devices with superior properties to the market. Realizing miniature optics at the UV frequency range in particular has been challenging as the available transparent materials have limited range of dielectric constants. In this work we introduce a low absorption loss and low refractive index dielectric material magnesium oxide, MgO, as an ideal candidate for metalenses operating at UV frequencies. We theoretically investigate metalens designs capable of efficient focusing over a broad UV frequency range (200–400 nm). The presented metalenses are composed of sub-wavelength MgO nanoblocks, and characterized according to the geometric Pancharatnam–Berry phase method using FDTD method. The presented broadband metalenses can focus the incident UV light on tight focal spots (182 nm) with high numerical aperture ($$\hbox {NA}\approx 0.8$$ NA ≈ 0.8 ). The polarization conversion efficiency of the metalens unit cell and focusing efficiency of the total metalens are calculated to be as high as 94%, the best value reported in UV range so far. In addition, the metalens unit cell can be hybridized to enable lensing at multiple polarization states. The presented highly efficient MgO metalenses can play a vital role in the development of UV nanophotonic systems and could pave the way towards the world of miniaturization.

A Simple Permittivity Calibration Method for GPR-Based Road Pavement Measurements

Frequenz ◽  
2016 ◽  
Vol 70 (9-10) ◽  
Author(s):  
Pekka Eskelinen
Keyword(s):  
Dielectric Material ◽  
Quality Measurement ◽  
Cavity Resonator ◽  
Calibration Method ◽  
Frequency Range ◽  
Cylindrical Resonator ◽  
Road Pavement ◽  
Asphalt Quality ◽  
Cylindrical Cavity Resonator

AbstractCylindrical resonator principle can be used in GPR asphalt quality measurement calibration. This method relies on ordinary drill core samples that are regularly taken from measured road sections, but now only analyzed for dimensions, density and sometimes chemically. If such a drill sample is covered with proper conductive surfaces, a cylindrical cavity resonator is formed. The baseline of the GPR permittivity recordings can so be found by measuring the resonance behaviour of this covered sample, which can later still be used for those traditional analyses. A clear benefit is the resonator’s 1–2 GHz frequency range which equals that of common commercial GPR systems. Example results and reference readings from known dielectric material are shown. The obtained uncertainty in this case study is 0.02 units of permittivity, when measuring the same sample repeatedly.

scholarly journals Planar Sensor for Material Characterization Based on the Sierpinski Fractal Curve

2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
P. H. B. Cavalcanti Filho ◽  
J. A. I. Araujo ◽  
M. R. T. Oliveira ◽  
M. T. de Melo ◽  
M. S. Coutinho ◽  
...  
Keyword(s):  
Material Characterization ◽  
Microwave Resonator ◽  
Frequency Range ◽  
Fractal Curve ◽  
High Permittivity ◽  
Full Wave ◽  
Low Permittivity

This paper presents a planar and compact microwave resonator sensor to characterize materials. The geometry of the resonator is based on the Sierpinski fractal curve and has four poles in the frequency range from 0.5 GHz to 5.5 GHz. Any of the four poles can be used to measure samples with low permittivity values, where the first pole is suitable for samples with high permittivity values. The sensitivity of the poles and return losses of the sensor are presented and obtained using a full-wave 3D simulator software. The device is manufactured and validated through a comparison between simulated and measured results.

CPW-Fed Circularly Polarized Slot Antenna

2017 ◽  
Vol 7 (10) ◽  
pp. 70
Author(s):  
Ajit Chandramohan Yadav ◽  
Shafiyoddin Badroddin Sayyad
Keyword(s):  
Frequency Band ◽  
Microstrip Antenna ◽  
Dielectric Material ◽  
Coplanar Waveguide ◽  
Impedance Matching ◽  
Dual Band ◽  
Slot Antenna ◽  
Frequency Range ◽  
Band Frequency ◽  
Circularly Polarized

This article demonstrates the coplanar waveguide (CPW) feed L- slot microstrip antenna for multi frequency band operation is presented. The proposed antenna is excited by a single CPW feed connected to a Microstrip antenna. In this radiating patch and feed are etched on the same dielectric material. A SMA connector is used to connect the feed strip which couples the energy to a radiating patch by capacitive feed. The length and width are designed to obtained dual band frequency range. A truncation is used for multiband operations and for proper impedance matching. L- slot is used to increase the depth of S11 parameter. 

scholarly journals New insights into reliability of electrostatic capacitive RF MEMS switches

2011 ◽  
Vol 3 (5) ◽  
pp. 571-586 ◽  
Author(s):  
Usama Zaghloul ◽  
George J. Papaioannou ◽  
Bharat Bhushan ◽  
Fabio Coccetti ◽  
Patrick Pons ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Material Characterization ◽  
Rf Mems ◽  
Dielectric Material ◽  
Dielectric Films ◽  
Mems Switches ◽  
Dielectric Charging ◽  
Rf Mems Switches ◽  
Metal Insulator Metal ◽  
Mim Capacitors

Among other reliability concerns, the dielectric charging is considered the major failure mechanism which hinders the commercialization of electrostatic capacitive radio frequency micro-electro-mechanical systems (RF MEMS) switches. In this study, Kelvin probe force microscopy (KPFM) surface potential measurements have been employed to study this phenomenon. Several novel KPFM-based characterization methods have been proposed to investigate the charging in bare dielectric films, metal–insulator–metal (MIM) capacitors, and MEMS switches, and the results from these methods have been correlated. The used dielectric material is plasma-enhanced chemical vapor deposition (PECVD) silicon nitride. The SiNx films have been charged by using a biased atomic force microscope (AFM) tip or by electrically stressing MIM capacitors and MEMS switches. The influence of several parameters on the dielectric charging has been studied: dielectric film thickness, deposition conditions, and under layers. Fourier transform infra-red (FT-IR) spectroscopy and X-ray photoelectron spectroscopy (XPS) material characterization techniques have been used to determine the chemical bonds and compositions, respectively, of the SiNx films. The data from the physical material characterization have been correlated to the KPFM results. The study provides an accurate understanding of the charging/discharging processes in dielectric films implemented in electrostatic MEMS devices.

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