• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.15 no.4
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• pp.143-152
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• 2016

In this paper, a MMIC double balanced mixer that can be applied to the tele-communication band is designed and LO power optimization for the mixer is discussed. The chip of the MMIC double-balanced mixer is fabricated on GaAs substrate with the size of $4{\times}4mm^2$. Optimization study of LO power for the MMIC double-balanced mixer proposed in this paper is conducted for the Input IP3 (IIP3) regarding on the linearity of the input signal. When LO power level of+16 dBm is applied to the mixer, IIP3 is obtained to be approximately 23.2 dBm, which is the most outstanding characteristic.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.15 no.3
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• pp.258-264
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• 2004

In this paper, MMIC double balanced star mixer for 40 ㎓ was implemented on GaAs substrate with backside vias. In the design of the MMIC mixer, the design of balun and diode was required. A novel balun structure using microstrip to CPS was presented. The 40 ㎓ balun was designed based on the design experience of the scale-down balun by 2 ㎓. The balun may be suitable for fabrication in MMIC process with backside via and can easily be applied for DBM(Double Balanced Mixer). A Schottky diode was designed and implemented using p-HEMT process considering the compatability with other high frequency MMIC's fabricated on p-HEMT base process. Finally, the double balanced star mixer was fabricated using the balun and the p=HEMP Schottky diode. The measured performance of mixer shows 30 ㏈ conversion loss at 18 ㏈m LO power. This insufficient performance is caused by the unwanted diode at AlGaAs junction in vertical structure of p-HEMT. If the p-HEMT's gate is recessed to AlGaAs layer, and so the diode is eliminated, the mixer's performances will be improved.

• Journal of Advanced Navigation Technology
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• v.17 no.2
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• pp.196-201
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• 2013

In this paper, a dual-mode balanced filter with symmetric coupled composite right/left-handed transmission line is introduced. Unlike the other symmetric structure, this configuration has the ability to operate under both common- and differential-mode excitation. These properties are achievable through providing physical short circuit by means of ground vias at the center of each unit-cell along the symmetry plane of the structure. Because the CRLH unit-cells are operated under both common- and differential-mode excitation, we implemented a balanced filter using these properties. To validity these features, a five-cell four port coupled CRLH-TL is simulated, fabricated and measured and the obtained performances agree with the simulation results under both common- and differential-mode excitation.

• Journal of Advanced Navigation Technology
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• v.15 no.1
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• pp.97-103
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• 2011

This paper presents a dual-band balanced mixer using nonlinear phase characteristic of composite right/left-handed (CRLH) transmission line. This metamaterial structure provides low LO leakage and high RF to LO isolation without additional filters for LO and RF path. The balanced mixer consists of balun and Wilkinson divider with dual-band characteristic of unit-cell which behaves like a CRLH metamaterial. Experimental results are used to verify the proposed metamaterial functions. The balanced mixer design results in an operating frequency of 870 MHz and 1660 MHz with an optimum mixer conversion loss of 15.2 dB at 870 MHz and 21.2 dB at 1660 MHz.

• Proceedings of the KIPE Conference
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• 2019.07a
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• pp.297-298
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• 2019

본 논문에서는 인덕터와 커패시터(LC)를 이용한 새로운 전압 밸런서(VB)를 제안한다. 제안한 VB는 하프-브리지 및 Neutral-Point-Clamped 구조처럼 이중 출력을 가진 Dual-Active-Bridge (DAB) 컨버터에 적용될 수 있다. 제안한 VB는 추가적인 스위칭 소자를 사용하지 않더라도 출력 부하 조건에 관계없이 출력 전압 평형을 유지할 수 있다. 제안한 VB를 사용할 때, 변압기와 출력의 중성점 사이에 LC가 추가되지만, 컨버터의 PWM 방식과 동작은 기존과 대부분 동일하다. 따라서, 제안한 VB를 사용하는 이중 출력 DAB 컨버터는 기존 이중 출력 DAB 컨버터의 장점을 대부분 유지한 상태로 출력 전압 평형을 달성할 수 있다. 3 kW 시제품을 제작하여 제안한 VB의 성능을 검증하였다.

• Cement
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• s.31
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• pp.23-28
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• 1969

Rotary kiln의 원만한 열평형과 경제적 운전을 목적으로 kiln inlet zone의 내화연와를 이중으로 축로하기도 하는데 당공장에서 실시간 one-layer lining과 two-layer lining과의 논리적 열손실량 비교 및 실제측정 결과에 대해 기술하고자 한다.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.15 no.6
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• pp.608-618
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• 2004

In this paper, modifying the diode star double balanced mixer of Maas, a novel resistive 60 GHz pHEMT MMIC star mixer is suggested. Due to star configuration, troublesome IF balun for ring configuration FET mixer is not necessary. In addition, the sysematic design method of dual balun through EM simulation is suggested rather than the design by inspection as Maas. The mixer circuit is fabricated as MMIC on CPW base using 0.1 um GaAs pHEMT Library of MINT in Dongguk University. The size is 1.5 ${\times}$ 1.5 $\textrm{mm}^2$ and its performance is adjustable by DC supply. It can be operated as both up and down converters and it shows the conversion loss of about 13∼18 ㏈ over the full V-band frequencies.

• Proceedings of the Korean Institute of Communication Sciences Conference
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• 1998.10a
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• pp.843-846
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• 1998

• Proceedings of the Korean Vacuum Society Conference
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• 2012.02a
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• pp.521-521
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• 2012

공정용 유도 결합 플라즈마에서 강자성체 페라이트를 이용하여 평형전력 공급 변압기를 사용하여 안정적인 고밀도 플라즈마 발생원 개발에 관한 연구를 수행하였다. 실험에서는2개의 평형전력 공급 변압기를 이중 구조 안테나에 설치하였다. 20-100 mTorr 압력 범위의 아르곤 기체에 30-150 W범위의 전력을 인가하여 반응용기의 중앙에서 부유 탐침법을 이용하여 플라즈마 밀도와 전자 온도를 측정하였다. 동일한 압력과 전력이 인가되었을 때, 평형전력 공급 변압기의 연결 유무에 따른 플라즈마 밀도를 비교하였으며, 본 연구에서 제시한 플라즈마 발생원에서의 플라즈마 밀도가 더욱 높음을 보였다. 또한 전자 온도와 부유 전위는 평행전력 공급방식을 이용한 플라즈마 발생원이 상대적으로 낮은 값을 가졌다. 이는 플라즈마 전위의 감소를 나타내며, 챔버 벽으로 빠져나가는 이온과 전자의 손실이 줄어들었음을 알 수 있다.

• Journal of the Korean Institute of Telematics and Electronics
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• v.14 no.6
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• pp.1-5
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• 1977

The input equivalent resistances and operating properties of a transless double balanced modulator are quantitatively investigated in considerations of the nonlinear characteristics of diodes. The input equivalent resistances are derived from the power loss calculations of the circuit. Carrier suppression and modulation efficiency are calculated by using approximate equations which describe the dynamic curves of the diode circuits. The results are represented as a function of the voltage amplitude of a carrier signal owing to the nonlinear characteristics of diodes.