• Journal of the Korea Institute of Information and Communication Engineering
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• v.14 no.11
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• pp.2397-2402
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• 2010

Dielectric resonator bandpass filters with various time-delay at 800MHz were designed and fabricated in this paper. from the results of this study. first of all, good response. characteristics were measured for all cases. The insertion loss was below 2dB and flatness for ripple was below 0.2dB, whereas return loss was over 20dB, respectively. The measured delay time of the fabricated prototype were 6ns, 12ns and 200s, respectively and the flatness characteristics did not exceeding Ins for all cases. Furthermore, 2~4ns of flatness were measured for 2-hole dielectric block and other dielectric resonator filters with various delay time by combination of each prototypes filters were also implemented.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.28A no.12
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• pp.19-23
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• 1991

A method for suppressing unwanted resonance modes by attaching an electromagnetic wave absorber onto a metal case was studied to prevent performance deterioration of electronic devices. The electromagnetic wave absorber fabricated for this study had an attenuation characteristics above 20dB in the frequency band from 450MHz, 1150MHz. A rectangular cavity resonator whose resonance frequencies of TE$_{101}$, TE$_{102}$ modes were 900MHz, 1250MHz, respectively, was made to measure attenuation for the electromagnetic wave absorber-metal assembly. The result showed that the resonance mode for high attenuation was sensitive to the location of electromagnetic wave absorber, and the attenuation characteristics above 20dB could be obtained when electromagnetic wave absorber was properly positioned.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.8 no.2
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• pp.107-115
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• 1997

In this paper, a 23 GHz push-push oscillator was designed and fabricated for 23 GHz point-to-point communication using split ring resonator. The split ring resonator was equivalent circuit and numerical method of MPIE(Mixed Potential Integral Equation). The analysis of split ring resonator which coupled between microstrip lines was carried out with transmission-mode using this results. The fabricated oscillator showed the output power of 4 dBm, the 1'st harmonic suppression of -20 dBc, the 3rd harmonic suppression of -34 dBc, a SSB phase noise of -109 dBc / Hz at 1MHz offset frequency from the carrier was achieved and 1.4 percents efficiency at 23 GHz. The experimental outputs were in good results with the theoretical and simulated results.

• 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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• 2001.05c
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• pp.19-24
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• 2001

In this study, Pb(La Ce)$TiO_3$ composition ceramics were manufactured for 20 MHz resonator application. Electromechanical coupling factor, mechanical quality factor and dynamic range of thickness vibration mode were measured as the variations of L/T(length/thickness) ratio of ceramic substrats. Mechanical quality factor and dynamic range of third overtone thickness vibration mode showed the highest value of 2,773 and 52.22 dB at specimen S4(l/t=12), respectively. The excellent temperature stability of resonant frequency suitable for resonator application was shown, regardless of thermal shock.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.14 no.9
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• pp.720-725
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• 2001

In this study, Pb(La,Ce)Ti $O_3$ ceramics were manufactured for 20 MHz resonator application. Electromechanical coupling factor( $k_{t}$, $k_{t3}$, mechanical quality factor( $Q_{mt}$ , $Q_{mt3}$ and dydnamic range (D.R) of thickness vibration mode were measured as the variations of $\ell$/t(length/thickness) ratio of ceramic substrates. Mechanical quality factor( $Q_{mt3}$) and dynamic range of third overtone thickness vibration mode showed the highest value of 2,773 and 52.22dB at specimen S4($\ell$/t=12), respectively. The excellent temperature stability of resonant frequency suitable for resonator application was shown, regardless of thermal shock.k.ock.k.

• 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).

• Journal of the Korea Institute of Information and Communication Engineering
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• v.16 no.4
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• pp.669-676
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• 2012

In this paper, The method to improve the mass production method of the radar sensor is suggested by using the temperature compensation circuit which is composed with the thermister. The mass production became easier by decreasing the adjustment time for the exact oscillation frequency with the temperature compensation circuit that can support the proper gate bias voltage for the FET after the dielectric resonator is removed from the DRO(Dielectric Resonator Oscillator) of the radar sensor. Radar sensor with the proposed method has 15.67MHz oscillator frequency variation in the temperature range of $-20^{\circ}C-+55^{\circ}C$, 0.65dB magnitude variation, -105.47dBc phase noise characteristics at 1MHz which are better or similar temperature characteristics with the DRO whose oscillator frequency variation is 25MHz, magnitude variation is 0.42dB and phase noise is -107.40dBc in the same temperature range.

• Journal of the Korean Institute of Telematics and Electronics
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• v.13 no.3
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• pp.11-15
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• 1976

한국산 천연수정은 보석장식용으로서는 그 품질이 이미 알려져 있으나 수정진동자로서의 특성에 관해서는 아직 보고된 바가 없다. 본 연구는 특히 경상도일대에서 채굴되고 있는 천연수정을 채집, 선별, 가공하여 그 수정진동자로서의 사용가능성을 실험을 통하여 검토한 것이다. 필자들은 채굴현장 근처에서 채집한 원석을 특별히 고안제작된 검사경을 이용하여 분석선별하였으며 X-ray를 사용하여 AT-cut로 orientation 한후 시판을 절단하였다. 다음 적용하여 전기적, 광학적 쌍수상태를 검토하고 다시 선별하였다 Dimensioning은 5MHz를 목표로 하였는데 연잠제를 사용하여 5MHz의 조도까지 연마하고 전극으로서 표준형의 은막을 부착하여 시판을 완성하였다. 시판을 대한 측정결과는 모든 등가정수가 대표적인 수입수정판의 것과 대등하였으며 특히 Q는 모두 105를 넘었다. 온도특성도 AT-cut의 이론치와 대차가 없었으며 -20℃-+100℃ 범위에서 최대 20PPM 이내의 편차를 보였다. 즉, 한국산 천연수정은 적절히 선별, 가공 한다면 부유한 수정진동자의 원재로서 사용할수 있음이 증명되었다. Samples of domestic natural quartz were collected and screened optically and chemically, and, after weeding out portions unfit for electrical resonator, were cut into AT-cut wafers, which in turn were dimensioned, trimmed and lapped into 5MHz resonator units. The results of measurements obtained from the specimens indicated excellent electrical characteristics of domestic natural quartz with the average Q quotient of 10s or higher. Temperature characteristics also showed typical AT-cut corves with the frequency deviation of 20PPM at maximum throughout the range of -20 to 100℃. The experiment on the initial batch of samples amply indicates the excellent electrical quality of domestic natural quartz as quartz resonator units.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.07a
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• pp.976-980
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• 2001

In this study, P $b_{0.88}$(L $a_{a}$N $d_{l-a}$)$_{0.08}$(M $n_{1}$3/S $b_{2}$3/)$_{0.02}$ $Ti_{0.98}$ $O_3$system ceramics were manufactured for 20 MHz class resonator application. Electromechanical coupling factor, mechanical quality factor and dynamic range of 3rd overtone thickness vibration mode were measured as the variations of La and Nd molar ratio. Mechanical quality factor and dynamic range at $\alpha$=0.6 composition ceramics showed the highest value of 2, 691 and 52.37 dB, respectively. The tempearture coefficient of resonant frequency measured from -2$0^{\circ}C$ to 8$0^{\circ}C$ showed an excellent value of 5ppm/$^{\circ}C$ at $\alpha$ = 1 composition ceramics. ceramics.s.