• ETRI Journal
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• 제28권4호
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• pp.529-532
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• 2006

This letter describes a compact printed helical resonator and its application to a microwave oscillator circuit implemented in coplanar waveguide (CPW) technology. The high quality (Q)-factor and spurious-free characteristic of the resonator contribute to the phase noise reduction and the harmonic suppression of the resulting oscillator circuit, respectively. The designed resonator showed a loaded Q-factor of 180 in a chip area of only 40% of the corresponding miniaturized hairpin resonator without any spurious resonances. The fully planar oscillator incorporated with this resonator showed an additional phase noise reduction of 10.5 dB at a 1 MHz offset and a second harmonic suppression enhancement of 6 dB when compared to those of a conventional CPW oscillator without the planar helical resonator structure.

• Journal of electromagnetic engineering and science
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• 제6권3호
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• pp.160-164
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• 2006

This paper describes a compact printed helical resonator and its application to a microwave oscillator circuit implemented in coplanar waveguide(CPW) technology. The high Q-factor and spurious-free characteristic of the resonator contribute to the phase noise reduction and the harmonic suppression of the resulting oscillator circuit, respectively. The designed resonator resonating at the frequency of 5.5 GHz showed a loaded Q of 180 in a chip area of only 40 % of the corresponding miniaturized hairpin resonator without any spurious resonances. The fully planar oscillator incorporated with this resonator showed additional phase noise reduction of 10.5 dB at 1 MHz offset and a second harmonic suppression enhancement of 6 dB when compared to those of a conventional CPW oscillator without the planar helical resonator(PHR) structure.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1997년도 추계학술대회 논문집 학회본부
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• pp.364-366
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• 1997

An experimental helical resonator plasma system that can be applied to the next generation semiconductor processing was fabricated and its characteristics was investigated. Helical resonator plasma can operate both in a capacitive and an inductive mode. Such sources will produce an extended plasma for the capacitive mode and a plasma concentrated in the resonator for the inductive mode. Plasma parameters were measured with Double Langmuir Probes. Plasma densities of $10^{11}{\sim}10^{12}cm^{-3}$ were produced in argon for pressure in the $2{\sim}120\;mTorr$ range. From the results, we conclude that helical resonator plasma can be applied to the next generation semiconductor processing.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2000년도 하계종합학술대회 논문집(2)
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• pp.282-285
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• 2000

Four helical resonators are distributed in a 2 ${\times}$ 2 array by modifying upper part of the conventional reactive ion etching(RIE) type LCD etcher in order to prepare a large area plasma source. Since the resonance condition of the RF signal to the helical antenna, one RF power supply is used for delivering the power efficiently to all four helical resonators without an impedance matching network Previous work of 2 ${\times}$ 2array inductively coupled plasma(ICP)requires one matching circuit to each ICP antenna for more efficient power deliverly Distributions of ion density and electron temperature are measured in terms of chamber pressure, gas flow rate and RF power . By adjusting the power distribution among the four helical resonator units, argon plasma density of higher than 10$\^$17/㎥ with the uniformity of better than 7％ can be obtained in the 620 ${\times}$ 620$\textrm{mm}^2$ chamber.

• 한국진공학회지
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• 제8권2호
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• pp.172-179
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• 1999

The axial distributions of plasma density in a helical resonator plasma with the external magnetic field have been measured using Langmuir probes. Net RF power is set to 200W and chamber pressure is varied from 0.4 mTorr to 100mTorr there are three kinds of eternal magnetic field structure applied on the helical resonator plasma. One is a uniform magnetic field, the second is a positive gradient magnetic field and the third is a negative gradient magnetic field. In the three magnetic field structures, the negative gradient magnetic field is found to show the highest increase in plasma density on the substrate compared with other magnetic structures. Plasma density profile in helical resonator is well consistent with electromagnetic field pattern obtained by computer simulation. It is also found that axial magnetic fields do not affect plasma density distribution in the plasma reactor region, but induce the increase of plasma density in the process chamber region. In order to avoid the nonuniformity of radial density profile, weak magnetic fields under 100G are applied.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제48권5호
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• pp.309-314
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• 1999

The magnetized helical resonator plasma etcher has been built. Electron density and temperature were measured as functions of rf source power, axial magnetic field, and pressure. The results show electron density increases as the magnetic field increases and reached $2\times1012cm^{-3}$,/TEX>. The oxide etch rate and selectivity to polysilicon were investigated as the above mentioned conditions and self-bias voltage. We can obtain the much improved oxide etch selectivity to polysilicon (60 : 1) by applying the external axial weak magnetic field in magnetized helical resonator plasma etcher.

• 한국재료학회:학술대회논문집
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• 한국재료학회 1996년도 재료학회 춘계학술발표회
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• pp.49-49
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• 1996

• 한국전자파학회논문지
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• 제22권9호
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• pp.820-826
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• 2011

본 논문에서는 자기 공명 방식의 무선 전력 전송 시스템에서 효율 향상 방안을 제시하였다. 공진 코일은 헬리컬과 스파이럴 형태가 결합된 구조를 제안하였으며, 소스와 디바이스 코일은 단일 원형 루프 형태로 설계하였다. 측정 결과, 송수전 코일이 120 mm의 거리로 이격되어 있을 때 헬리컬과 스파이럴 구조를 결합한 공진기는 기존의 헬리컬 구조의 공진기보다 효율이 13 % 향상되는 결과를 보였다. 뿐만 아니라, 크기도 기존 공진기에 비해 33 % 소형화할 수 있었다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1997년도 추계학술대회 논문집 학회본부
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• pp.376-378
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• 1997

Plasma density and its axial distribution and uniformity on the substrate in a helical resonator plasma in the external magnetic field have been measured using Langmuir probes. Net RF power is set to 200W and chamber pressure is varied from $1{\times}10^{-1}Torr$ to $1{\times}10^{-4}Torr$. There are three kinds of external magnetic field structure applied on the helical resonator plasma. One is a uniform magnetic field, another is a plus gradient magnetic field and the third is a minus gradient magnetic field. Of the three magnetic field structure, the minus gradient magnetic field is found to show the highest increase in plasma density on the substrate compared with other magnetic structures. In order to avoid radial density ununiformity, weak magnetic fields under 100Gauss are applied.

• 한국산학기술학회논문지
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• 제10권10호
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• pp.2639-2645
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• 2009

본 논문은 나선형 공진기를 이용한 CPW 발진기의 설계에 대하여 기술한다. CPW 나선형 공진기는 기존의 CPW 헤어핀, 헬리컬 공진기에 비하여 높은 Q 특성을 가지므로 출력특성과 크기가 개선된 발진기 설계에 유리하다. CPW 발진기 설계에 앞서 세 가지 CPW 공진기의 특성을 비교한다. EM 시뮬레이션을 행하여 공진기 설계 및 발진기 성능 확인에서의 정확도를 높였음을 보인다. 세 가지 CPW 공진기를 이용하여, 5.7 GHz 대역에서 각각 발진기를 설계하였다. 제작 및 측정 결과, 헬리컬, 헤어핀, 나선형 공진기를 이용한 각각 CPW 발진기의 측정된 출력은 각각 2.55 dBm, 2.64 dBm, 4.98 dBm이다. 한편 세 가지 공진기는 각각 $102.15mm^2,\;130.05mm^2,\;80.625mm^2$ 크기를 보여, 제안한 CPW 나선형 공진기가 다른 공진기에 비해 크기 감소 효과도 우수함이 제시된다.