The Microwave Dielectric Materials of (Zn1-xMgx)TiNb2O8 for Electroceramics Devices Applications

2013 ◽  
Vol 547 ◽  
pp. 49-55 ◽  
Author(s):  
Cheng Liang Huang ◽  
Sen Hung Huang ◽  
Ruei Zhung Lee
Keyword(s):  
Wireless Lan ◽  
Microstrip Line ◽  
Bandpass Filter ◽  
Microwave Dielectric Properties ◽  
Dielectric Materials ◽  
Frequency Stability ◽  
Dielectric Substrates ◽  
Microwave Dielectric ◽  
5 Ghz ◽  
Filter Area

The microwave dielectric properties of ZnTiNb2O8 ( ~34, Qf ~42,500GHz, ~ –52ppm/°C) was reported by Hong et. al. To lower the dielectric loss of ZnTiNb2O8, we studied the systems of (Zn1-xMgx)TiNb2O8 (x=0.02-0.1) ceramics. The manner of equivalent-charge trace substitutions for Zn2+-sites were replaced with Mg2+. In order to achieve more stability, CaTiO3 ( ~ +800ppm/°C) was used to adjust the negative τf of (Zn0.95Mg0.05)TiNb2O8 ( ~ –58ppm/°C). A bandpass filter using coupled microstrip-line resonators have been designd for wireless LAN system such as IEEE 802.11 ( 2.4 or 5 GHz). The response of the implemented filter used 0.8(Zn0.95Mg0.05)TiNb2O8-0.2 CaTiO3 ( ~35.77, Qf ~18,000GHz, ~ +4ppm/°C) dielectric substrates. In this paper, the bandpass filter area designed on 0.8(Zn0.95Mg0.05)TiNb2O8-0.2 CaTiO3 is reduced 88% than FR4 substrates and the near zero τf makes better frequency stability.

B-O Bond Character and Microwave Dielectric Properties of (1-x)CaTiO3-xCa(Zn1/3Nb2/3)O3 Perovskite Ceramics

2009 ◽  
Vol 421-422 ◽  
pp. 69-72
Author(s):  
Jie Shen ◽  
Wen Chen ◽  
Jing Zhou ◽  
Jie Zhu ◽  
Qiong Lei
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Microwave Dielectric Properties ◽  
Dielectric Materials ◽  
Solid State Reaction Method ◽  
Dielectric Constants ◽  
Identical Result ◽  
Microwave Dielectric ◽  
Calculation Results ◽  
The Relationship

The relationship between the character of the B-site cation–oxygen bond and the microwave dielectric properties in perovskites dielectric materials was studied in this paper. The atomic net charge of CaTiO3 (CT) and Ca(Zn1/3Nb2/3)O3 (CZN) was calculated respectively. The calculating result implies that the covalency of B-O bonds in CZN is stronger than that in CT. This predicted that the dielectric constant and loss of the ceramics will decrease after CZN incorporated in CT. To confirme the prediction, (1-x)CT-xCZN microwave dielectric ceramics were prepared by solid state reaction method with ZnNb2O6 as precursor. The structure analysis in terms of tolerance factor gives an identical result as calculation. The microwave dielectric properties, such as dielectric constants, Q×f values and τf were studied as a function of composition. With x increasing from 0.2 to 0.8, the dielectric constant linearly decreases from 109 to 49.37, the Q×f value increases from 8,340 to 13,200 GHz, and τf decreases from 321 to -18 ppm/°C. The properties trends are consistent with the previous calculation results, and confirm the relationship between the character of B-O bond and dielectric properties.

scholarly journals Wireless Network Enhancement in the Arctic by Selection of Dielectric Materials of Rooms

2020 ◽  
Vol 9 (3) ◽  
pp. 524-530
Keyword(s):  
Dielectric Constant ◽  
Wireless Lan ◽  
Data Transfer ◽  
Short Circuit ◽  
Dielectric Materials ◽  
The Arctic ◽  
Telecommunication Infrastructure ◽  
5 Ghz ◽  
Mimo Technology ◽  
Multilayer Materials

The Arctic is of fundamental military-strategic importance for Russia. The development of the Arctic without an advanced telecommunication infrastructure is very difficult. To supply working in the Arctic employees with universal means of communication, it is the most efficient to use wireless communication band between 2.4 GHz and 5 GHz. Facilities, where radio telecommunication equipment in the Arctic works, have walls consisting of a multilayer structure. There is the problem of organizing communication of good quality. In such rooms, the best method is to use wireless networks using MIMO technology. We have developed a theory that allows us to determine the time Interflection T based on the determination of the dielectric constant of multilayer materials. In this case, problems arise in determining this coefficient. We propose to use the well-known method of short circuit and idling. We conducted a large number of measurements to determine the dielectric constant of various materials. We used this value to calculate the time T. In the future, we made adjustments to the premises by changing the size and amount of multilayer materials. Experimental results in the range from 2.4 GHz to 5 GHz showed that the data transfer rate increased by 5-10% when we performed the calculation of time Interflection and processed the room with multilayer materials. The proposed method is applicable indoors to build a wireless LAN standard IEEE 802.11 n.

scholarly journals Influence of mechanical activation on synthesis and properties of the MgO-TiO2 system

2007 ◽  
Vol 39 (1) ◽  
pp. 59-65 ◽  
Author(s):  
Vera Petrovic ◽  
A. Maricic ◽  
N. Labus ◽  
M.M. Ristic
Keyword(s):  
Dielectric Properties ◽  
Mechanical Activation ◽  
Microwave Dielectric Properties ◽  
Particle Morphology ◽  
Dielectric Materials ◽  
Magnesium Carbonate ◽  
High Energy ◽  
Crystal Modification ◽  
Type I ◽  
Microwave Dielectric

Materials applied in electronics such as multilayer capacitors are an important field of ceramic materials. Magnesium titanate based dielectric materials are used for producing type-I capacitors. A common way of obtaining this material is a solid-state reaction during reaction sintering. The process of sintering can be enhanced if mechanical activation precedes. In this work starting powders of magnesium carbonate (MgCO3) and titanium dioxide (TiO2) with a rutile crystal modification were weighed to attain a 1:1 molar MgCO3:TiO2 ratio. Mechanical activation of the starting mixture was performed by high energy ball milling using ZrO balls and vessels with a ball to powder mass ratio of 40:1. The observed grinding times were 15, 30, 60 and 120 minutes. Powder characterization was conducted using X ray powder diffraction, DTA analysis up to 1000 o C and particle morphology changes were observed with Scanning Electron Microscopy. Isothermal sintering of compacted powders was conducted at 1100?C during 30, 60 and 180 minutes. For specimens synthesized in such a manner, microwave dielectric properties were measured, quality factor Q, specific electrical resistivity (?) and the dielectric constant (?r). In this work we explain the influence of mechanical activation on the MgCO3-TiO2 system leading to titanate formation during sintering, as well as induced changes in microwave dielectric properties.

scholarly journals The latest process and challenges of microwave dielectric ceramics based on pseudo phase diagrams

2021 ◽  
Vol 10 (5) ◽  
pp. 885-932
Author(s):  
Hongcheng Yang ◽  
Shuren Zhang ◽  
Hongyu Yang ◽  
Qingyu Wen ◽  
Qiu Yang ◽  
...  
Keyword(s):  
Dielectric Material ◽  
Synthesis Method ◽  
Microwave Dielectric Properties ◽  
Dielectric Materials ◽  
Microwave Dielectric Ceramics ◽  
Structure Property ◽  
Extrinsic Factors ◽  
Intrinsic Polarization ◽  
Microwave Dielectric ◽  
Dielectric Ceramics

AbstractThe explosive process of 5G communication evokes the urgent demand of miniaturized and integrated dielectric ceramics filter. It is a pressing need to advance the development of dielectric ceramics utilization of emerging technology to design new materials and understand the polarization mechanism. This review provides the summary of the study of microwave dielectric ceramics (MWDCs) sintered higher than 1000 from 2010 up to now, °C with the purpose of taking a broad and historical view of these ceramics and illustrating research directions. To date, researchers endeavor to explain the structure-property relationship of ceramics with multitude of approaches and design a new formula or strategy to obtain excellent microwave dielectric properties. There are variety of factors that impact the permittivity, dielectric loss, and temperature stability of dielectric materials, covering intrinsic and extrinsic factors. Many of these factors are often intertwined, which can complicate new dielectric material discovery and the mechanism investigation. Because of the various ceramics systems, pseudo phase diagram was used to classify the dielectric materials based on the composition. In this review, the ceramics were firstly divided into ternary systems, and then brief description of the experimental probes and complementary theoretical methods that have been used to discern the intrinsic polarization mechanisms and the origin of intrinsic loss was mentioned. Finally, some perspectives on the future outlook for high-temperature MWDCs were offered based on the synthesis method, characterization techniques, and significant theory developments.

Microwave Dielectric Characteristics of Butyl Rubber- Barium Titanate Composites

2012 ◽  
Vol 2012 (CICMT) ◽  
pp. 000428-000435
Author(s):  
J. Chameswary ◽  
M. T. Sebastian
Keyword(s):  
Barium Titanate ◽  
Relative Permittivity ◽  
Volume Fraction ◽  
Filler Content ◽  
Microwave Dielectric Properties ◽  
Theoretical Models ◽  
Butyl Rubber ◽  
Microwave Dielectric ◽  
Tan Δ ◽  
5 Ghz

Butyl rubber-micron barium titanate (BR/BT) and butyl rubber-nano barium titanate (BR/nBT) composites were prepared by sigma mixing followed by hot pressing. The tensile tests show that both the composites were mechanically flexible. The microwave dielectric properties of both BR/BT and BR/nBT composites were investigated as a function of ceramic loading and were found to be improved with filler content. The butyl rubber has relative permittivity (εr) of 2.4 and loss tangent (tan δ) of 0.0017 at 5 GHz. At a filler loading of 0.24 volume fraction (vf) of micron sized barium titanate (BaTiO3) powder loading, the composite attained a εr of 7 and tan δ of 0.014 and for the same filler content of nano BaTiO3 the composite have εr of 8.9 and tan δ of 0.019 at 5 GHz. The thermal stability of the relative permittivity of both the composites was investigated. The experimental values of εr of both BR/BT and BR/nBT composites were compared with theoretical models.

An interdigital bandpass filter embedded in LTCC for 5-GHz wireless LAN applications

2005 ◽  
Vol 15 (5) ◽  
pp. 357-359 ◽  
Author(s):  
Gangqiang Wang ◽  
M. Van ◽  
F. Barlow ◽  
A. Elshabini
Keyword(s):  
Wireless Lan ◽  
Bandpass Filter ◽  
5 Ghz

scholarly journals Modeling and Measurements of Novel Monolithic Filters

2008 ◽  
Vol 2008 ◽  
pp. 1-8
Author(s):  
Aly H. Aly ◽  
Badawy El-Sharawy ◽  
Adalbert Beyer
Keyword(s):  
Dielectric Constant ◽  
Quality Factor ◽  
Bandpass Filter ◽  
Narrow Band ◽  
Dielectric Materials ◽  
Ferroelectric Materials ◽  
Dielectric Substrates ◽  
High Dielectric Materials ◽  
High Dielectric ◽  
Multilayer Dielectric

This paper presents novel multilayer tuneable highQ-filters based on hairpin resonators including ferroelectric materials. This configuration allows the miniaturization of these filters to a size that makes them suitable for chip and package integration and narrow-band applications. The main focus was miniaturizing filters with coupled loops using multilayer dielectric substrates. A further goal was to increase the quality factor of these distributed filters by embedding high dielectric materials in a multilayer high- and low-k(dielectric constant) substrate that is supported by LTCC technology. An improved W-shape bandpass filter was proposed with a wide stopband and approximately 5% bandwidth.

scholarly journals Investigation of Surface Scaling, Optical and Microwave Dielectric Studies of Bi0.5Na0.5TiO3 thin Films

2021 ◽  
Author(s):  
Srinivas Pattipaka ◽  
Pamu D ◽  
Pundareekam Goud J ◽  
James Raju K C ◽  
Gbinda Pradhan ◽  
...  
Keyword(s):  
Thin Films ◽  
Dielectric Properties ◽  
Microwave Dielectric Properties ◽  
Secondary Phase ◽  
Close Relation ◽  
Degree Of Crystallinity ◽  
Microwave Dielectric ◽  
Potential Applications ◽  
Tan Δ ◽  
5 Ghz

Abstract Herein, we have investigated the optical and microwave dielectric properties of Bi 0.5 Na 0.5 TiO 3 (BNT) thin films grown under different oxygen pressure ( P O2 ) using pulsed laser deposition (PLD) technique. The X-ray diffraction measurements confirms the single phase of BNT along with secondary phase and further reduction in secondary phase and increase in BNT phase with P O2 , signifies the close relation between the crystal structure and oxygen content. The shift of Raman-active TO1, TO2 and TO3 modes towards higher wavelengths and increase in mode intensity with P O2 indicating the films degree of crystallinity. The local roughness ( α loc ) of all films obtained as ~ 0.85, and the interface width ( w ) and lateral correlation length ( ξ ) of films varies with P O2 . Also, the films exhibit the increase in refractive index and reduction in optical bandgap of due to improvement in crystallinity and reduction in the oxygen vacancies. The microwave dielectric properties show a strong P O2 depends with higher dielectric constant ( ε r = 336) with lower loss (tan δ = 0.0093) at 5 GHz which show the potential applications in high frequency devices.

Microwave Dielectric Properties of LTCC Materials Consisting of BaO-TiO2-SiO2-Al2O3 Glass - BaNd2Ti5O14 Ceramic Composites

2005 ◽  
Vol 486-487 ◽  
pp. 506-509 ◽  
Author(s):  
Yu Jin Kim ◽  
Seong Jin Hwang ◽  
Hyung Sun Kim
Keyword(s):  
Dielectric Properties ◽  
Glass Ceramic ◽  
Microwave Dielectric Properties ◽  
Dielectric Materials ◽  
Ceramic Composites ◽  
Sintering Behavior ◽  
Shape Stability ◽  
Low Dielectric ◽  
Microwave Dielectric ◽  
Quality Factor Q

The desirable characteristics of the microwave materials include excellent dielectric constant εr, low dielectric loss (high quality factor, Q*f0 value), and small temperature coefficient (~0ppm/°C) of resonant frequency (Tf). The advantages of using a glass-ceramic include shape stability during the sintering stage, improved dielectric properties, mechanical strength, and controlled thermal expansivity. In the present study, glass-ceramic compositions consisting of a glass system (BaO-TiO2-SiO2-Al2O3) and a ceramic filer (BaNd2Ti5O14) were prepared. The glass and glass-ceramic compositions were evaluated for sintering behavior such as shrinkage, densities, thermal properties, and microstructures. In addition, the microwave dielectric properties (≈ 15~20 for εr, > 6000 GHz for Q*f0) were determined by a network analyzer at 6-8 GHz. These results suggest that the compositions can be a candidate for LTCC dielectric materials.

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