Temperature stable Sm(Nb1-xVx)O4 (0.0 ≤ x ≤ 0.9) microwave dielectric ceramics with ultra-low dielectric loss for dielectric resonator antenna applications

2021 ◽  
Author(s):  
Fangfang Wu ◽  
Di Zhou ◽  
Chao Du ◽  
Shi-Kuan Sun ◽  
Lixia Pang ◽  
...  
Keyword(s):  
Dielectric Resonator ◽  
Structure Refinement ◽  
Far Infrared ◽  
Crystal Structure Refinement ◽  
Microwave Dielectric Ceramics ◽  
Dielectric Resonator Antenna ◽  
Low Dielectric ◽  
Microwave Dielectric ◽  
Transmission Electron ◽  
Dielectric Ceramics

Herein, structure and dielectric properties of Sm(Nb1-xVx)O4 (SNV-x) (0.0 ≤ x ≤ 0.9) ceramics were studied by crystal structure Refinement, Raman, Transmission electron microscope (TEM), Far-infrared / THz reflectivity spectroscopy...

Temperature stable Li2Ti0.75(Mg1/3Nb2/3)0.25O3-based microwave dielectric ceramics with low sintering temperature and ultra-low dielectric loss for dielectric resonator antenna applications

2020 ◽  
Vol 8 (14) ◽  
pp. 4690-4700 ◽  
Author(s):  
Huan-Huan Guo ◽  
Di Zhou ◽  
Chao Du ◽  
Peng-Jian Wang ◽  
Wen-Feng Liu ◽  
...  
Keyword(s):  
Dielectric Resonator ◽  
Sintering Temperature ◽  
Microwave Dielectric Ceramics ◽  
Dielectric Resonator Antenna ◽  
Excellent Performance ◽  
Low Dielectric ◽  
Microwave Dielectric ◽  
Small Density ◽  
Low Sintering Temperature ◽  
Dielectric Ceramics

The LTMN0.25 + 1 wt% 0.6CuO–0.4B2O3 ceramic with low sintering temperature, small density and excellent performance have wide application prospects in 5G devices.

Lattice Parameters of Bronze-Type 3BaO·2R2O3·9TiO2 (R=Sm and Nd) Solid Solutions for Microwave Dielectric Ceramics

1993 ◽  
Vol 37 ◽  
pp. 79-85 ◽  
Author(s):  
Hitoshi Ohsato ◽  
Toshiyuki Ohhashi ◽  
Kazuhiko Sumiya ◽  
Shinya Suzuki ◽  
Takashi Okuda
Keyword(s):  
Low Temperature ◽  
High Dielectric Constant ◽  
Dielectric Constants ◽  
Dielectric Resonators ◽  
Microwave Dielectric Ceramics ◽  
Low Dielectric ◽  
Satellite Broadcasting ◽  
Microwave Dielectric ◽  
Dielectric Ceramics ◽  
High Dielectric

Microwave dielectric ceramics with high quality have received attention due to the rapid progress in microwave telecommunication and satellite broadcasting. The desirable properties in microwave dielectric resonators are a high dielectric constant (εr), low dielectric loss (tanδ) (i.e. high Q (Q =1/tanδ)), and low temperature coefficient of the resonant frequency(τf). Properties of dielectric ceramics in the TiO2-rich region of the BaO-Nd2O3-TiO2 ternary system (Fig. 1) were reported to have excellent dielectric constants, low dielectric losses and low temperature coefficients of capacitance by Kolar et al. (1978).

Preparation of BaSm2Ti4O12 Microwave Dielectric Ceramics via a Polyacrylamide Precursor

2007 ◽  
Vol 336-338 ◽  
pp. 252-254
Author(s):  
Xian Li Huang ◽  
Fu Ping Wang ◽  
Qiu Sun ◽  
Ying Song
Keyword(s):  
Ceramic Powder ◽  
Microwave Dielectric Properties ◽  
Chelating Agent ◽  
Cavity Method ◽  
Microwave Dielectric Ceramics ◽  
Microwave Dielectric ◽  
Transmission Electron ◽  
Dielectric Ceramics ◽  
Quality Factor Q ◽  
Modified Polyacrylamide

A modified polyacrylamide precursor method is presented to synthesize BaSm2Ti4O12 microwave dielectric ceramics. Under an alkaline circumstance, all the cations together with the monomer and bridging agent were dispersed into a hydrous solution with the aid of chelating agent EDTA. This mixture was initiated at about 90°C, dried, calcined at 1000°C for 2hs and finally turned into well-crystallized and single-phased BaSm2Ti4O12 ceramic powder, which was modeled and sintered at 1250°C for 2hours into well-sintered ceramics. Differential thermal analysis, thermogravimetric analysis, X-ray powder diffraction and transmission electron microscope were used to characterize the process. Microwave dielectric properties measured by a resonating cavity method contain a dielectric constant (εr) about 77.0 and quality factor (Q×f) lager than 11000.

scholarly journals Ordered Domains and Microwave Properties of Sub-micron Structured Ba(Zn1/3Ta2/3)O3 Ceramics Obtained by Spark Plasma Sintering

Materials ◽  
2019 ◽  
Vol 12 (4) ◽  
pp. 638
Author(s):  
Fei Liu ◽  
Shaojun Liu ◽  
Xuejiao Cui ◽  
Lijin Cheng ◽  
Hao Li ◽  
...  
Keyword(s):  
Spark Plasma Sintering ◽  
Annealing Temperature ◽  
Microwave Dielectric Ceramics ◽  
X Ray Diffraction ◽  
X Ray ◽  
Microwave Dielectric ◽  
Plasma Sintering ◽  
Transmission Electron ◽  
Spark Plasma ◽  
Dielectric Ceramics

The degree of Zn2+ and Ta5+ ions ordering could play an important role in the dielectric loss in Ba(Zn1/3Ta2/3)O3 (BZT) ceramics. However, the influence of the grain size of Ba(B′1/3B″2/3)O3 ceramics with nano or sub-micron grains on the ordering domains structure is still not clear. In the present paper, highly dense (~98%) BZT microwave dielectric ceramics with homogeneous sub-micron structure (~330 nm) were prepared through spark plasma sintering (SPS). High resolution transmission electron microscopy combined with X-ray diffraction (XRD)clearly showed that the B-site ordering structure of sintered BZT samples by SPS becomes the B-site long-range 1:2 ordering as annealing proceeds. In contrast, the short-range 1:2 ordering in non-annealed counterparts was also present, which was not detectable by XRD. The size of B-site ordering domains enlarged with annealing temperature. The sub-micron structure of sintered BZT ceramics by SPS remained stable at up to 1400 C; however, the size of B-site 1:2 ordering domain was more than five times larger, which led to a significant increase of the quality factor (Q·f) to 37,700 GHz from 15,000 GHz.

Perovskite NdTiO3 in Sr- and Ca-doped BaO–Nd2O3–TiO2 Microwave Dielectric Ceramics

1999 ◽  
Vol 14 (4) ◽  
pp. 1576-1580 ◽  
Author(s):  
R. Ubic ◽  
I. M. Reaney ◽  
W. E. Lee
Keyword(s):  
Recent Work ◽  
Dielectric Resonator ◽  
Secondary Phase ◽  
Microwave Dielectric Ceramics ◽  
Microwave Frequencies ◽  
Microwave Dielectric ◽  
Dielectric Ceramics ◽  
Orientational Relationship

Ba6–3xNd8+2xTi18O54 (BNT) is a useful dielectric resonator at microwave frequencies. Recent work has shown that the major secondary phase in this system can be indexed as Nd4Ti9O24 (JCPDS 33–943). The present study has evealed that when half of the stoichiometric Ba+2 is replaced with Ca+2 or Sr+2, a third, tilted perovskite-structured phase, NdTiO3, is also present. It forms as coherent intragranular regions within BNT grains and always contains some of the divalent dopant species. The orientational relationship between NdTiO3 and BNT has been established.

Low-fired fluoride microwave dielectric ceramics with low dielectric loss

2019 ◽  
Vol 45 (1) ◽  
pp. 279-286 ◽  
Author(s):  
Xiao-Qiang Song ◽  
Kang Du ◽  
Jie Li ◽  
Xue-Kai Lan ◽  
Wen-Zhong Lu ◽  
...  
Keyword(s):  
Dielectric Loss ◽  
Microwave Dielectric Ceramics ◽  
Low Dielectric ◽  
Microwave Dielectric ◽  
Dielectric Ceramics
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