• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.15 no.1
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• pp.44-50
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• 2004

In this paper, a DBM(Doubly Balanced Mixer) of 2 GHz is implemented on FR4 substrate. The structure of doubly balanced mixer requires, in general, two batons and a quad diode. For balun, a novel planar balun using microstrip to CPS is suggested and designed. The suggested balun shows the phase imbalance of 180$^{\circ}$${\pm}$ 1.5$^{\circ}$and the amplitude imbalance of ${\pm}$ 0.2 ㏈ for 1.5 to 2.5 GHz. Using the balun, DBM is succesfully implemented, and the measured conversion loss of up/down converter show about 6 ㏈ over the bandwidth. The balun may be applicable for MMIC DBM with the process supporting backside via thourgh more study.

• Proceedings of the Korea Institute of Applied Superconductivity and Cryogenics Conference
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• 2002.02a
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• pp.358-361
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• 2002

The millirneterwave high-T$_{c}$ superconducting(HTS) down-converter sub-system with the HTS/III-V integrated mixer as the central device is demonstrated first. The constituent components of HTS down-converter sub-system such as a single balanced type integrated mixer with rat-race coupler, a cavity type bandpass filter (26 GHz), and a HTS planar lowpass filter(1 GHz), semiconductor LNA and IF-power amplifier, a driving electronic module for A/D converter, and a Stirling type mini-cooler module were combined into an International stand- and rack of 19-inch. From the RF(-61 dBm, 26.5GHz)and LO signal(-1 dBm, 25.6 GHz), IF signal(0dBm, 0.9 GHz) agreed with simulated results is obtained.d.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.8 no.2
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• pp.227-231
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• 2004

A MMIC (Monolithic Microwave Integrated Circuit) mixer chip using the schottky diode of InGaAs/CaAs p-HEMT process has been developed for receiver down converter of Ka-band. A different approach of MMIC mixer structure is applied for reducing the chip size by the exchange of ports between IF and LO. This MMIC covers with RF (30.6∼31.0㎓)and IF (20.8∼21.2㎓). According to the on-wafer measurement, the MMIC mixer with miniature size of 3.0mm1.5mm demonstrates conversion loss below 7.8㏈, LO-to-RF isolation above 27㏈, LO-to-IF isolation above 19㏈ and RF-to-IF isolation above 39㏈, respectively.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.10
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• pp.437-443
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• 2018

This study investigates the effect of the mixing elements on the pressure loss and mixing performance in line mixer. The high density ozone water devices mixed with gas and liquid are used in various fields such as sterilizing of group feeding facilities and water quality management at a fish farm. Due to the decrease in rainfall due to climate change, pasteurization of drinking water from ground water and surface water is extremely important. Therefore, it is intended to develop a line-mixed gas liquid mixer with a small amount of space. In this study, the effects of the number of static mixers and the types and the number of the orifice used in line mixer on the volume fraction and the pressure loss were studied by CFD simulation. The pressure drops of line mixer with orifice which curved vanes were attached to were down to more than 50 percent of that of line mixer with static mixer whereas the mixing performance of the former was similar to that of the latter.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.47 no.2
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• pp.100-105
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• 2010

In this paper, a FM radio receiver integrated circuit has been developed based on $0.5{\mu}m$ CMOS process for Zero-Crossing FM demodulator over the 88MHz to 108MHz band. The receiver is designed with the low-IF architecture, and includes Low Noise Amplifier(LNA), Down-Conversion Mixer, Phase Locked Loop(PLL), IF LPF, and a comparator. The measured results of the LNA and Mixer show that the conversion gain of 23.2 dB, the input PldB of -14 dBm, and the noise figure of 15 dB. The measured analog block of the LPF and comparator show the voltage gain of over 89 dB, and the IF LPF can configure the passband from 600KHz to 1.3MHz with 100KHz step through the internal control register banks. The designed FM radio receiver operates at 4.5V with the total current consumption of 15.3mA, so the total power consumption is about 68.85mW. The commercial FM radio has been successfully received.

• JSTS:Journal of Semiconductor Technology and Science
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• v.6 no.2
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• pp.114-118
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• 2006

In this paper, the effect of base and collector structures on DC, small signal characteristics of SiGe HBTs fabricated by RPCVD was investigated. The structure of SiGe HBTs was designed into four types as follows: SiGe HBT structures which are standard, apply extrinsic-base SEG selective epitaxial growth (SEG), apply selective collector implantation (SCI), and apply both extrinsic-base SEG and SCI. We verified the devices could be applied to the fabrication of RFIC chip through a fully integrated 2.4 GHz down-conversion mixer.

• Proceedings of the KSME Conference
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• 2008.11b
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• pp.2495-2500
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• 2008

We simulated the mixing characteristics in micro T-channel using Lattice Boltzmann Method. We studied the relation a mixing length and pressure-drop due to inlet and outlet ration in Reynolds number 0.5, Peclet number 500 and Schmidt 1000. The ratio of a down-inlet to up-inlet was $0.5{\sim}1.5$ times, up-inlet to outlet was $1{\sim}3$ times and outlet length was 250 times to up-inlet. The mixing length decrease linearly as outlet ratio decreased, and pressure-drip increase non-linearly. Initial stage of micro channel mixture was fast by down-inlet ratio, however, the mixing length is not influence.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.12 no.1
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• pp.65-70
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• 2001

This paper presents a Receiver MMIC for the CDMA terminal. The complete circuit is composed of Low Noise Amplifier, Down Conversion Mixer, Intermediate Frequency Amplifier and Bias circuit. The Bias circuit implementation, which allows for compensation for threshold voltage and power supply voltage variation are provided. The proposed topology has high linearity and low noise characteristics. Results of the designed circuit are as follows: Overall conversion gain is 28.5 dB, input IP3 of LNA is 8 dBm, input IP3 of down conversion mixer is 0 dBm and total DC current consumption is 22.1 mA.

• 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 the Korea Institute of Information and Communication Engineering
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• v.4 no.3
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• pp.527-536
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• 2000

This paper discusses the design of self-oscillating mixer type low noise down converter using the microwave field effect transistor. The mixer is consists of local oscillator in which high stability dielectric resonator and band pass filter to get rid of spurious oscillation at intermediate frequency stage. The microstrip antenna was integrated in the same substrate which generate 12.3GHz and low noise amplifier was also added after antenna using 3 stage of high electron mobility transistors. The output frequency from the local oscillator was chosen as 11.3GHz for the Ku-band application. The measured phase noise was -804dBc/Hz at 100kHz offset frequency, and the gain was 7～12dB in frequency range from 12.0GHz to 12.7GHz. The noise figure at intermediate frequency stage was 64H. The designed model shows less conversion loss than previous diode type mixer. The proposed mixer can be used in digital satellite broadcasting and communication system and expected to use in next generation low noise block design.