Polaron conduction loss in microwave dielectric ceramics

1999 ◽  
Vol 14 (2) ◽  
pp. 500-502
Author(s):  
Seungbum Hong ◽  
Eunah Kim ◽  
Han Wook Song ◽  
Jongwan Choi ◽  
Dae-Weon Kim ◽  
...  
Keyword(s):  
Quality Factor ◽  
Phonon Scattering ◽  
Dielectric Resonators ◽  
Frequency Range ◽  
Conduction Loss ◽  
Microwave Dielectric ◽  
Scattering Effects ◽  
Unloaded Quality Factor ◽  
Dielectric Ceramics ◽  
Polaron Conduction

It has been generally accepted that the product of the unloaded quality factor and resonant frequency is the universal parameter for comparison of dielectric resonators with different size.1,2 However, it is suggested in this study that this universal parameter should be modified due to the presence of the polarons. From the frequency dependence of the unloaded quality factor, it is possible to extract the factor determined only by the phonon scattering effects, and we denoted this parameter by Qs. It was found that the Qs parameter for ZrxSnzTiyO4 (ZST) and Ba(Zn1/3Ta2/3)O3 (BZT) ceramics showed constancy in the frequency range of 2–12 GHz, which supports the idea of polaron conduction loss contribution to the dielectric loss.

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).

A high improved quality factor of Li2MgTi3O8 microwave dielectric ceramics system

2014 ◽  
Vol 123 ◽  
pp. 195-197 ◽  
Author(s):  
Ping Zhang ◽  
Yue Wang ◽  
Jian Liu ◽  
Zhenkun Song ◽  
Yemei Han ◽  
...  
Keyword(s):  
Quality Factor ◽  
Microwave Dielectric Ceramics ◽  
Microwave Dielectric ◽  
Dielectric Ceramics

Sintering Temperature Influence on Microwave Dielectric Properties of TiO2-ZrO2 Ceramics

2010 ◽  
Vol 660-661 ◽  
pp. 646-651
Author(s):  
José Vitor C. Souza ◽  
Pedro José Castro ◽  
Maria do Carmo de Andrade Nono ◽  
Sergio Luiz Mineiro
Keyword(s):  
Dielectric Properties ◽  
Sintering Temperature ◽  
Microwave Dielectric Properties ◽  
Dielectric Constants ◽  
Dielectric Resonators ◽  
Temperature Influence ◽  
X Ray Diffraction ◽  
X Ray ◽  
Microwave Dielectric ◽  
Dielectric Ceramics

Dielectric ceramics have been widely investigated and used for microwave applications such as resonators and filters. The present study deals with the influence of sintering temperature on microwave dielectric properties of TiO2 ceramics with 10, 20, and 30 wt% ZrO2. Three compositions have been developed through mixing procedures and then tested for each sintering temperature: 1500 and 1400 °C. X-ray diffraction and scanning electron microscopy are carried out aiming to explain the ceramic behavior of each sample. The dielectric constants of different ceramics for both temperatures varied from 85.4 to 62.6, while their quality factor due to dielectric losses varied from 3110 to 1630. The Q decrease is attributed to the non uniform grain growth and to the obtained crystalline phases. The best microwave parameters were obtained for the ceramics sintered at 1400 °C, which can be applied in microwave circuits as dielectric resonators.

High quality factor microwave dielectric ceramics in the (Mg1/3 Nb2/3 )O2 -ZrO2 -TiO2 ternary system

2017 ◽  
Vol 100 (9) ◽  
pp. 3982-3989 ◽  
Author(s):  
Wen-Bo Li ◽  
Di Zhou ◽  
Li-Xia Pang ◽  
Yan-Zhu Dai ◽  
Ze-Ming Qi ◽  
...  
Keyword(s):  
Ternary System ◽  
Quality Factor ◽  
High Quality Factor ◽  
Microwave Dielectric Ceramics ◽  
High Quality ◽  
Microwave Dielectric ◽  
Dielectric Ceramics
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