• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.05c
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• pp.71-74
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• 2002

In this study, resonant characteristics of $Pb_{0.88}(La_{0.6}Nd_{0.4})_{0.08}(Mn_{1/3}Sb_{2/3})_{0.02}Ti_{0.98}O_3$ ceramics were investigated with the variations of electrode radius size for manufacturing the best 30MHz SMD type ceramic resonator with the size of $3.7{\times}3.1{\times}0.255mm^3$. Physical properties were proper for appling for 30MHz SMD type ceramic resonator. In third overtone thickness vibration mode, with increasing electrode radius size, resonant resistant($Z_r$) was decreased gradually. Mechanical quality factor($Q_{mt3}$) and dynamic range(D.R) showed the maximum value of 2,283, 47.1dB respectively, at 0.74mm electrode radius size.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.16 no.3
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• pp.202-206
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• 2003

In this study, modified PbTi $O_3$ ceramics was manufactured to apply for 30MHz SMD type ceramic resonator with the variations of electrode weight. To investigate the effects of electrode weight on resonant characteristics of ceramic resonator using 3$^{rd}$ overtone thickness vibration mode, ceramic wafers for resonator were fabricated by evaporating electrode weights of 0.66, 1.765, 2.32, 3.87$\times$ 10$^{-4}$ g/c $m^2$ with silver, respectively. And then, SMD type ceramic resonators were fabricated with the size of 3.7$\times$3.1mm and electrode radius size of 0.77mm. With increasing electrode weight, resonant resistance was gradually decreased. At the electrode weight of 2.32$\times$10$_{-4}$ g/c $m^2$, mechanical quality factor( $Q_{mt3}$) and dynamic range(D.R) showed the maximum value of 2,152 and 49dB, respectively.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.15 no.8
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• pp.671-677
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• 2002

In this study, the high frequency SMD ceramic resonators with the size of $3.7{\times}3.1{\times}0.385\textrm{mm}^3$ were fabricated using $Pb_{0.88}(La_{0.6}Nd_{0.4})_{0.08}(Mn_{1/3}Sb_{2/3})_{0.02}Ti_{0.98}O_3$ ceramics with the variations of electrode radius size. With increasing the electrode radius size, resonant resistance in third overtone mode was decreased and electromechanical coupling factor($k_{t3}$) in third overtone mode was showed constant values. Taking into consideration mechanical quality factor($Qm_{t3}$) of 5,552 and dynamic range(D.R) of 60.72dB in third overtone mode, the ceramic resonator with the electrode radius size of $\theta$1.13mm was suitable for 20MHz resonator application.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.11b
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• pp.446-450
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• 2001

In this study, microstructural and electrical properties of (Pb)(La,Nd)$TiO_3$ cerramics were investigated as a function of CuO addition. Taking into consideration Tc of $325^{\circ}C$, dynamic range of 49dB( at the wafer form) and density of $7.71g/cm^{3}$, it can be concluded that the specimen S2 sintered at $1200^{\circ}C$ is the best for the resonator application, Dynamic characteristics of energy-trapped 20MHz SMD type resonator as a function of internal dot size variation were also investigated. Dynamic range characteristics showed the highest value of 60.72dB at S2-4(dot size 1.13mm).

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.11a
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• pp.446-450
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• 2001

In this study, microstructural and electrical properties of (Pb)(La,Nd)TiO$_3$ ceramics were investigated as a function of CuO addition. Taking into consideration Tc of 3$25^{\circ}C$, dynamic range of 49dB( at the wafer form) and density of 7.71g/㎤, it can be concluded that the specimen S2 sintered at 120$0^{\circ}C$ is the best for the resonator application. Dynamic characteristics of energy-trapped 20MHz SMD type resonator as a function of internal dot size variation were also investigated. Dynamic range characteristics showed the highest value of 60.72dB at S2-4(dot size 1.13mm).

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.07a
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• pp.684-688
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• 2001

The structural, piezoelectric and dynamic range characteristics of modified PbTi $O_3$ceramics were investigated as a function of Mn $O_2$addition. With the increase of Mn $O_2$addition, Curie temperature was decreased. As the increase of Mn $O_2$addition, mechanical quality factor ( $Q_{mt3}$) in the third over tone thickness mode was increased. Dynamic range in the third over tone thickness mode was also increased with the increase of Mn $O_2$addition. The composition ceramics added to 0.075wt% Mn $O_2$showed the best properties for SMD type resonator using third over tone thickness vibration in terms of high Curie temperature more than 31$0^{\circ}C$ and dynamic range of 49.38dB.B.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.24 no.2
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• pp.122-127
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• 2013

Layered-type dielectric waveguide filters were designed. As the order of layers increased the fabrication process for dielectric waveguide filters which the resonator parts were connected by the lateral direction has many difficulties. The proposed structure in this report was designed based on the layered-type for the some parts of resonators. The size of layered-type dielectric waveguide filters installed on the PCB surface were reduced at 25% as compared with the usual waveguide filters by using a relative dielectric constant 22.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.24 no.10
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• pp.958-963
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• 2013

Ceramic dielectric waveguide duplexer was developed. Duplexer was designed in order to minimize the muture interferences between transmission port and receive port of bandpass filter. The design method for antenna port was determined by the transmission loss and calibrated the length of resonator of recriving filter. We used the ceramic powder of dielectric constant 9.46 and installed SMD type on PCB board.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.1355-1356
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• 2007

SMD type 압전레조네이터 제작을 위한 압전 조성물을 찾고자 PLT 세라믹스에 B-site Ti 자리에 Mn을 치환시키고 소결첨가제로서 CuO를 첨가하였다. $0{\sim}0.4wt%$ CuO를 첨가하여 1150, 1200, $1250^{\circ}C$로 각각 소결한 후 소결온도 및 CuO 첨가량에 따른 압전 및 유전특성을 관찰하였다. CuO 첨가량에 따라 1150, $1200^{\circ}C$ 소결시 밀도가 증가하였고, $1250^{\circ}C$ 소결시 기계적 품질계수가 증가하였다. 소결온도 $1250^{\circ}C$, 0.1wt% CuO 첨가시 밀도, 전기기계 결합계수(kp), 유전상수, 기계적 품질계수는 7.5[g/cm3], 0.1, 253, 1776을 각각 나타내었다.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.40 no.3
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• pp.1-9
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• 2003

In this paper, we designed a highly suppressed sidelobe ladder type RF SAW bandpass filter based on 1-port resonator, for 800 MHz mobile communication system. In order to get the highest device characteristics, we optimized some important parameters such as the electrode thickness, electrode lambda weghting of the reflectors, and static capacitance ratio. Furthermore, we fabricated the Tx and Rx. filter using optimized parameters. Implemented filters can be used in 800 MHz mobile communication system and external impedance matching circuits are not needed. RF filter was fabricated on 36$^{\circ}$LiTaO$_3$ substrates with Al-Cu (W 3 %)and mounted 3.8mm$\times$3.8mm$\times$1.5mm SMD package. Developed filters has 2.3 dB insertion loss in the 25 MHz pass-band, 33MHz with 3-dB insertion loss, stop-band rejection of 30 dB, passband ripple is less than 0.5 The power durability of the filters measured about 3.5W and the maximum temperature variation within -2$0^{\circ}C$~8$0^{\circ}C$ was 0.09 dB/$^{\circ}C$ of 3-dB insertion loss.