• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.24 no.10
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• pp.964-970
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• 2013

This paper presents a bandpass wireless 3-D chip to chip interface technique. The proposed technique uses direct amplitude modulation of the free running oscillator which especially utilizes the coupling capacitance between two stacked chips as a part of the resonator. Therefore, the oscillator is three dimensionally configured and a simple envelope detector can be used as a receiver without any additional matching circuitry. The proposed link was designed and fabricated using 110 nm CMOS technology and experimental results successfully showed the data transmission at a data rate of 2 Gb/s for the stacked chips with a thickness of 50 ${\mu}m$ consuming 4.32 mW. The sizes of the Tx and Rx chips are 0.045 $mm^2$ and 0.029 $mm^2$, respectively.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.2A
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• pp.91-99
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• 2011

Several repeater systems are used to enhance the cell coverage to location such as shadow and rural areas in mobile systems. But the general RF repeater solutions are not suitable for high power outdoor environment because it has the weakness such as self oscillation problem With adoption of a adaptive digital filter technology, feedback interference cancellation repeater prevents oscillation by detecting and canceling the unwanted feedback signal between transmission and receiver antenna. In this paper, dual NLMS based interference cancellation method is proposed and the step size adaptation can be implemented by the estimation of the feedback channel Doppler frequency characteristics. The performance of the proposed algorithm is quantified via analysis and simulation for the static and multipath fading feedback channels.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.21 no.5
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• pp.453-458
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• 2010

In this work, a 18 GHz divide-by-4 injection-locked frequency divider(ILFD) based on ring oscillator has been developed in $0.13-{\mu}m$ Si RFCMOS technology. The free-running oscillation frequency is from 4.98 to 5.22 GHz and output power is about －30 dBm, consuming 33.4 mW with a 1.5 V supply voltage. At 0 dBm input power, the locking range is 3.5 GHz(17.75~21.25 GHz) and with varactor tuning, the operating range is increased up to 5.25 GHz(16.0~21.25 GHz). The fabricated chip size is $0.76\;mm{\times}0.57\;mm$ including DC and RF pad.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.5 no.6
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• pp.1143-1150
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• 2001

In this paper, we designed a downconverter for K-band satellite multipoint distribution service(SMDS). The designed downconverter consists of a low noise amplifiers, bandpass filter, stable local oscillator, drain mixer and If Amplifiers. Low noise amplifiers show 28㏈ gain and 1.5㏈ noise figure in the frequency range of 19.2㎓~20.2㎓, and a band pass filter has a -l㏈ insertion loss, and 18.25㎓ Stable local oscillator which is dielectric resonant oscillation, We obtained that the output power of the 18.25㎓ oscillation frequency is 0.5㏈m and the phase noise is the -84.67㏈c at 10KHz offset frequency. With the input RF signal the 19.2㎓~20.2㎓, conversion gain of the drain mixer shows 5㏈ at the Intermediate frequency range of 950MHz~1950MHz. We have proved that the designed downconverter satisfied the specification of a K-band satellite multipoint distribution service and it can be applied to the satellite internet receiver.

• Journal of the Korea Society of Computer and Information
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• v.10 no.1 s.33
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• pp.175-180
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• 2005

Transmission speed becomes high speedization gradually in system while is the latest microwave and millimeter wave communication and user's demand is trend that also increase rapidly. To accommodate wider band width therefore, signalman who have high frequency and not required welsh suppression special quality little more is required. Designed oscillator, point Parts, in duplex all communication systems several systems studies that can keep pace with a lot of amount of informations in modern info-age are archieved vigrously.

• Proceedings of the Korean Institute of Communication Sciences Conference
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• 2004.07a
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• pp.308-308
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• 2004

• Journal of Sensor Science and Technology
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• v.8 no.2
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• pp.108-114
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• 1999

Surface acoustic wave (SAW) device is very attractive for gas sensor applications because of their small size, low cost, high sensitivity, and good reliability. A dual delay line surface acoustic wave $NO_2$ gas sensors have been designed and fabricated on the $LiTaO_3$ piezoelectric single crystal substrate. The capacitance of the fabricated IDTs was 326.34pF at the frequency of 79.3MHz. The maximum reflection loss of the impedence-matched IDTs was -16.74dB at the frequency of 79.3MHz. The SAW oscillator was constructed and the stable oscillation was obtained by controlling the gain of rf amplifier properly. The oscillation frequency shift of the SAW oscillator to the $NO_2$ gas was 28Hz/ppm.

• Proceedings of the Optical Society of Korea Conference
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• 2003.07a
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• pp.270-271
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• 2003

링 레이저 자이로스코프는 회전각을 검출하는 센서로서 광학식이 가지는 정밀함과 견고성으로 관성항법을 비롯한 운동 제어를 필요로 하는 여러 분야에서 기존의 기계식 자이로스코프를 대체해 오고 있다. 링 레이저 자이로는 세 개 또는 네 개의 반사경으로 밀폐된 고리형 공진기를 구성하고 He-Ne 기체를 봉입하여 방전시킴으로써 서로 반대 방향으로 진행하는 레이저를 동시에 발진시키면 Sagnac 효과에 의해 공진기의 회전각에 비례하여 두 레이저의 주파수 차이가 발생하는 원리를 이용한다. (중략)

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.8 no.4
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• pp.243-248
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• 2015

Since phase noise is one of the most important parameters in the design of microwave oscillators, several methods have been proposed to reduce the phase noise. These methods have focused on improving the quality factor of resonators, which result in low phase noise oscillators. Dielectric resonators have been widely used for low phase noise in microwave oscillators due to their high quality factor. However this cannot be used in MMIC oscillators because they have a 3D structure. In this paper, to overcome this problem a novel resonator using open ring type DGS is proposed for improvement of phase noise characteristics that is weak point of oscillator using planar type microstrip line resonator, and oscillator for 5.8GHz band is designed using proposed DGS resonator. The open ring type DGS resonator is composed of DGS cell etched on ground plane under $50{\Omega}$ microstrip line. At the fundamental frequency of 5.8GHz, 6.1dBm output power and -82.7 dBc@100kHz phase noise have been measured for oscillator with ring type DGS resonator. The phase noise characteristics of oscillator is improved about 96.5dB compared to one using the general ${\lambda}/4$ microstrip resonator.

• Journal of IKEEE
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• v.3 no.1 s.4
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• pp.79-85
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• 1999

In this paper, the resistive mixer for 5.86Hz wireless LAN, main part receiving system, was designed and implemented. The noise characteristics and the linearity in the base band was superior. For the use of local oscillator of mixer, dielectric resonator of stable output and temperature characteristics was designed. For the electrical tuning by the capacitance variation of varactor diode, the microstrip line and magnetic coupling characteristics of the dielectric resonance was used. It was obtained that gain of the proposed resistive mixer containing the RF cable loss, is -13.8dB, the conversion loss of frequency converter is -12 dB, and the output power of local oscillator is 1.67 dBm.