Dielectric Constant and Loss Tangent of Silicon at 700–900 GHz at Cryogenic Temperatures

2019 ◽  
Vol 29 (7) ◽  
pp. 501-503 ◽  
Author(s):  
Kangmin Zhou ◽  
Sylvain Caroopen ◽  
Yan Delorme ◽  
Michele Batrung ◽  
Maurice Gheudin ◽  
...  
Author(s):  
A. Ege Engin ◽  
Abdemanaf Tambawala ◽  
Madhavan Swaminathan ◽  
Swapan Bhattacharya ◽  
Pranabes Pramanik ◽  
...  

2016 ◽  
Vol 78 (6-2) ◽  
Author(s):  
See Khee Yee ◽  
Samsul Haimi Dahlan ◽  
Mohd Zarar Mohd Jenu ◽  
Chee Kiong Sia

This paper presents the method to predict the shielding effectiveness of cement powder mixed with different amount of graphite powder. Cement mixed with different percentage of graphite is prepared. Their dielectric constant and loss tangent are measured based on the transmission/reflection technique using APC7 connector. The measured data is fed into Artificial Neural Network (ANN) for training. When the training process is completed the neural network is used to predict the dielectric constant and loss tangent of cement-graphite mixture that contains different amount of graphite. The comparison shows that the trained neural network is very successful to predict the dielectric constant and loss tangent of cement-graphite mixture. The proposed graphical user interface has made the process of shielding effectiveness prediction becomes more user friendly especially for those designers who are not familiar with the analytical calculation of shielding effectiveness and dielectric measurement.


2012 ◽  
Vol 512-515 ◽  
pp. 1180-1183
Author(s):  
Qian Qian Jia ◽  
Hui Ming Ji ◽  
Shan Liu ◽  
Xiao Lei Li ◽  
Zheng Guo Jin

The (Ba, Sr)TiO3 (hereafter BST) ceramics are promising candidate for applying in tunable devices. MgO coated BST-Mg2TiO4 (BSTM-MT) composite ceramics were prepared to obtain the low dielectric constant, low dielectric loss, good dielectric constant temperature stability, and high tunability of BST ceramics. The Ba0.55Sr0.40Ca0.05TiO3 nanoparticles were coated with MgO using the precipitation method and then mixed with Mg2TiO4 powders to fabricate BSTM-MT composite ceramics. The morphologies, phases, elements, and dielectric properties of the sintered ceramics were investigated. The core-shell structure of BST powder wrapped with MgO was clearly observed from the TEM image. After sintered at 1100 °C for 2 h, the composite ceramics expressed dense microstructures from SEM images and two main phases BST and Mg2TiO4 were detected in the XRD patterns. The dielectric constant and loss tangent were both reduced after the coating. The reduced dielectric constant and loss tangent of BSTM-MT were 190, 0.0011 (2MHz), respectively. The ceramics exhibited the diffuse phase transition near the Curie temperature and the Curie temperature shifted from 10 °C to 5 °C after the coating. Since the continuous Ti-O bonds were disconnected with the MgO coating, the tunability was reduced to 15.14 % under a DC bias field of 1.1 kV/mm. The optimistic dielectric properties made it useful for the application of tunable capacitors and phase shifters.


1993 ◽  
Vol 115 (2) ◽  
pp. 219-224 ◽  
Author(s):  
R. K. Agarwal ◽  
A. Dasgupta

A mechanistic model is presented for predicting the effective dielectric constant and loss tangent of woven-fabric reinforced composites with low-loss constituents. A two-scale asymptotic homogenization scheme is used to predict the orthotropic effective properties. A three-dimensional unit-cell enclosing the characteristic periodic repeat pattern in the fabric weave is isolated and modeled mathematically. Electrostatic boundary value problems (BVP’s) are formulated in the unit-cell and are solved analytically to predict effective dielectric constant of the composite, using three-dimensional series-parallel reactance nets. Results are also verified numerically, using finite element methods. The effective dielectric constant and the effective loss tangent are then obtained, analogous to mechanical viscoelastic problems for low-loss materials. The predicted dielectric constant and loss tangent are compared with experimental results for E-glass/epoxy laminates. Frequency dependence of the effective dielectric constant and loss tangent is obtained from the corresponding behavior of the constituent materials. Trade-off studies are conducted to investigate the effect of the constituent material properties on orthotropic effective dielectric permittivity.


2008 ◽  
Vol 368-372 ◽  
pp. 47-49
Author(s):  
Jian Ling Zhao ◽  
Xiao Hui Wang ◽  
Long Tu Li ◽  
Xi Xin Wang ◽  
Yang Xian Li

BaTiO3 films with a thickness up to 3 μm were fabricated under the hydrothermal conditions. It was found that the crystallinity of BaTiO3 increases with the concentration of Ba(OH)2 solutions. Along with the increasing of time, the crystallinity of BaTiO3 increases, reaches the maximum value and then decreases. The measured values of remanent polarization (Pr) and coercive field (Ec) are 1.74μC/cm2 and 24KV/cm. The leakage of the films at 1V is 10-7A/cm2. The dielectric constant and loss tangent of hydrothermal derived BaTiO3 film at a frequency of 1 KHz were 600 and 0.2, respectively.


Sign in / Sign up

Export Citation Format

Share Document