• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.14 no.2
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• pp.119-126
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• 2003

In this paper, a cylindrical cavity resonator oscillator with high Q factor is designed and fabricated to improve the phase noise characteristic. A cavity resonator is coupled to oscillating circuit using aperture hole. Measured results show that the cylindrical cavity resonator oscillator (CRO) for Ku-band has less phase noise than the dielectric resonator oscillator (DRO) with the same oscillating circuit. It has output power of +3.92 dBm at the center frequency 13.4015250 GHz and phase noise of -109 dBc/Hz at 100 kHz offset.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.7 no.1
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• pp.68-74
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• 2008

The substrate integrated waveguide (SIW) structure can be approximated as the rectangular waveguide using common dielectric substrate with via-holes. To realize reflection-type resonator, $50-{\omega}$ microstrip line can be used for coupling with the center plane of the cavity. The oscillator is designed to operate at 9.45 GHz using the reflection-type SIW cavity resonator. The phase noise of oscillator shows -98.1dBc/Hz at 100 KHz offset. In experiment, the reflection type SIW cavity resonator improves the loaded quality factor making the low phase noise oscillator possible. Due to the entirely planar structure of this resonator, this technique can also be adequate in oscillator applications for a low cost and low phase noise performance.

• Journal of electromagnetic engineering and science
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• v.5 no.4
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• pp.153-160
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• 2005

In this paper, the novel microwave oscillator incorporating a planar cavity resonator(PCR) is presented to reduce the phase noise of the oscillator in a planar environment. Compared to the conventional planar( $\lambda$/4 open stub resonator), the phase noise is improved about 16 dBc/Hz @100 kHz. The design of the oscillator is based on a reflection type configuration using the low 1/f SiGe HBT transistor(LPT16ED). The output power is measured 2.76 dBm at 12.5 GHz. In this paper, the oscillator used to the PCR can be expected to provide a solution for low phase noise oscillator in microwave circuits.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.22 no.2
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• pp.174-177
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• 2009

In this paper, an oscillator using dielectric-rod loaded cavity resonators with HTS(High Temperature Superconductor) end-plates was presented. It was operated at X-band. A two port cavity resonator was incorporated into a basic feedback loop oscillator configuration. A rutile loaded cavity resonator with HTS thin film end-plates was used to provide the quality factor between $10^4$ and $10^6$. A parallel feedback oscillator was constructed with a dielectric loaded cavity resonator, an amplifier, and a directional coupler. At 300 K, the experimental results showed the phase noise of -108 dBc/Hz at a 100 kHz offset frequency. At 26 K, the results was -118.8 dBc/Hz at same offset frequency.

• 한국ITS학회:학술대회논문집
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• v.2007 no.10
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• pp.144-148
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• 2007

• Journal of Korea Society of Digital Industry and Information Management
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• v.10 no.2
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• pp.37-45
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• 2014

This paper is a study of the water sensor using a coaxial cavity resonator. This water sensor uses the resonant frequency variation of the coaxial cavity resonator when there is a water drop of the used coaxial cavity resonator. And we made resonant frequencies by controlling the input voltage of the oscillator which will be mainly resonated in the coaxial cavity resonator. First, we made the coaxial cavity resonator by simulating the resonator structure with the proposed size and we expect the resonant frequency from the simulation and then we decide the VCO from the result. Second, we made the water drop detecting sensor circuit and measured the water sensor. We decided the size of the resonator as inner conductor 5mm, outer conductor 14mm, the height of resonator 9.5mm, and the height of the glass 6mm from the simulated result. The simulated resonant frequencies are 3.09GHz and we made the VCO frequency ranges from 2.56GHz to 3.2GHz. The measured resonant frequency is 2.97GHz and the return loss is under -8. 4 dB at the center frequency. When the water is dropped on the glass of the resonator, the voltage has changed from 690mV to 145mV. It shows the proposed water sensor can detect the water by the resonant frequency variation of the resonator.

• 한국초전도학회:학술대회논문집
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• v.12
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• pp.47-47
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• 2002

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.23 no.4
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• pp.468-474
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• 2012

A low phase-noise microwave oscillator is presented by a substrate integrated waveguide(SIW) loading a complementary split ring resonator(CSRR) in this paper. The unloaded $Q$-factor of the SIW cavity is increased by loading a complementary split ring resonator(CSRR) and its value exhibits 1960. It is theoretically and experimentally demonstrated that the proposed circuit generates 11.3 dBm of output power at 9.3 GHz and a phase-noise of -127.9 dBc/Hz at 1-MHz offset.

• Journal of Radiation Protection and Research
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• v.42 no.1
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• pp.21-25
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• 2017

Background: We are developing L-band and S-band microwave dielectric absorption systems aiming novel dosimetry using DNAs, such as plasmid DNA and genomic DNA, and microwave technology. Materials and Methods: Each system is composed of a cavity resonator, analog signal generator, circulator, power meter, and oscilloscope. Since the cavity resonator is sensitive to temperature change, we have made great efforts to prevent the fluctuation of temperature. We have developed software for controlling and measurement. Results and Discussion: By using this system, we can measure the resonance frequency, f, and ${\Delta}Q$ (Q is a dimensionless parameter that describes how under-damped an oscillator or resonator is, and characterizes a resonator's bandwidth relative to its center frequency) within about 3 minutes with high accuracy. Conclusion: This system will be expected to be applicable to DNAs evaluations and to novel dosimetric system.

• Journal of the Korean Institute of Telematics and Electronics
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• v.19 no.5
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• pp.20-25
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• 1982

A realization method of the microwave oscillator is proposed by the inherently stable transistor with a cavily resonator feedback loop. The real Part of the output impedance of the inherently stable bipolar transistor can be made to be negative at the resonance frequency by the high-Q cavity feedback loop, and the oscillation condition can be obtained with the matching section of the load. In this work the microwave transistor oscillator is realized with a silicon bipolar transistor HXTR 2101 and a reentrani cavity, and characteristic of the output power 10m Watts at 2.33 GHz osc. frequency can be verified experimentally.