• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.10A
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• pp.958-964
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• 2005

In this thesis, the matching network at the local oscillator port of the sub-harmonic mixer is optimized for reducing the conversion loss. A downconverter for point to point system applications is designed and fabricated using the such sub-harmonic mixer. The sub-harmonic mixer achieved the conversion loss of 11.8 dB at the 12 dBm input power of the local oscillator and the isolation of less than -40 dB. The downconverter achieved the IF output power flatness of 2 dB and the total noise figure of 5.9 dB.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.33A no.6
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• pp.81-89
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• 1996

Quantum RF impedance of SIS (superconductor insulator superconductor) junction has been analyzed by using through on tucker's quantum mixer theory in the frequency range form 80 GHz to 120 GHz. The embedding impedance of waveguide-type mixer mount and its equivalent circuit have been evaluated. From these evaluated results, the impedance matching efficiency between mixer mount embedding impedance and mixer port impedance of upper-side band and IF which were determined by augmented admittance matrix with given backshort position has been discussed in detail. It is found that the mixer with fixed backshort mount ahs a impedance matching efficiency about 80% at each port of mixer within 85GHz to 115GHz, which implys a conversion los of mixer would be good enough to be operated such a wide band frequency range. Therefore, the theoretical evaluated results show that our method can be used ot design the mixer mount without any mechanical tuning elements such a backshort or an E-plane tunners for wide band operation.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.11 no.8
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• pp.1392-1398
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• 2000

In this paper, Sub Harmonic Ring Mixer using Anti-Parallel Diode Pair is studied. Conventional mixers mix LO signal with RF signal and, obtain IF signal from the difference between LO and RF. Sub harmonic ring mixers using APDP mix RF signal with the second harmonic of LO signal, LO frequency needed for conventional receiver is reduced by 1/2.The produced mixer showed 12 dB conversion loss, and 1 dB compression point of IF signal, in respect to RF signal, was found at the 0 dBm RF signal. Isolation LO/IF and LO/RF is 24.6 dB and 22.5 dB respectively. Isolation RF/LO and LO/RF is 32.6 dB and 22.5 dB respectively.

• Journal of Advanced Navigation Technology
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• v.10 no.2
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• pp.138-144
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• 2006

In this paper, dual mode FET mixer for WiBro and wireless LAN(WLAN) applications has been designed in the form of dual gate FET mixer by using the cascode structure of two single gate pHEMTs. The designed dual gate mixer has been optimized to have variable conversion gain for WiBro and WLAN applications in order to save dc power consumption. The LO to RF isolation of the designed mixer is more than 20dB from 2.3GHz to 2.5GHz band. With the LO power of 0dBm and RF power of -50dBm, the mixer shows 15dB conversion gain. When RF power increases from -50dBm to -20dBm, the conversion gain decreases to -2dB from 15dB with bias change. The variable conversion gain has several advantages. It can reduce the high dynamic range requirement of AGC burden at IF stage. Also, it can save the dc power dissipation of mixer up to 90%.

• The Journal of the Korea institute of electronic communication sciences
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• v.15 no.5
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• pp.827-834
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• 2020

In this paper, a third-order harmonic mixer is designed using frequency multiplier theory for the microwave airborne radar. Unlike the basic mixer design method, the gate bias voltage, at which the third-harmonic component of the Local frequency (LO) is the maximum, is selected using a frequency multiplier theory to maximize the third-harmonic mixing component at the intermediate frequency (IF). The proposed harmonic mixer was designed and manufactured using a commercial GaAs MESFET device in a plastic package, and it was possible to improve the high conversion loss, circuit complexity, high cost, and manufacturing complexity of the existing microwave mixer. The harmonic mixer using the proposed design method has a -8 ~ -10 dB conversion loss by pumping 11.5 GHz LO with a +5 dBm level when operating from 33.0 GHz to 36.0 GHz and the 1-dB gain compression point (P1dB) of 0 dBm.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.22 no.5
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• pp.538-544
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• 2011

This paper presents a compact single balanced diode mixer fabricated using a 0.1 ${\mu}M$ GaAs p-HEMT commercial process for an E-band frequency up/down converter. This mixer includes a LO balun employing a Marchand balun with a good RF performance. In order to improve the port-to-port isolation, a high pass filter and a low pass filter are include in this mixer at the RF and IF ports, respectively. The fabricated mixer with a very compact size of 0.58 mm2(0.85 mm${\times}$0.68 mm) exhibits a conversion loss of 8～12 dB and an input P1dB of 1～5 dBm at the LO power of 10 dBm from 71～86 GHz.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.4A
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• pp.350-357
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• 2005

DSRC provides high speed radio link between Road Side Equipment and On-Board Equipment within the narrow communication area. In this paper, a 5.8 GHz up-conversion mixer for DSRC communication system was designed and fabricated using 0.8 m SiGe HBT process technology and IF/LO/RF matching circuits, IF/LO input balun circuits, and RP output balun circuit were all integrated on chip. The chip size of fabricated mixer was $2.7mm\times1.6mm$ and the measured performance was 3.5 dB conversion gain, -12.5 dBm output IP3, 42 dB LO to If isolation, 38 dB LO to RF isolation, current consumption of 29 mA for 3.0 V supply voltage.

• Proceedings of the IEEK Conference
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• 2003.07a
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• pp.434-437
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• 2003

In this paper, we have developed a frequency mixer for the microwave phase conjugator. The circuit topology is the gate mixer using a pseudomorphic HEMT device. The operating frequencies are 4.0 GHz 2.01 GHz, and 1.99 GHz for LO, RF, and IF, respectively. Conversion gain is measured to be 12 dB and 1 dB compression point -34 dBm at the LO power of -4 dBm.

• Proceedings of the Korea Electromagnetic Engineering Society Conference
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• 2001.11a
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• pp.279-282
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• 2001

Ka-Band MMIC Mixer 칩 을 InGaAs/GaAs p-HEMT 공정의 Schottky Diode을 이용하여 개발하였다 설계된 칩은 상/하향 주파수 변환기로 사용할 수 있으며 Double Balance 구조로 되어있다. 크기 3.0$\times$2.4 $\textrm{mm}^2$ 칩의 On-wafer측정 결과, RF주파수 24～27 GHz와 LO주파수 16.28 GHz, IF 주파수 7.72～10.72GHz 상/하향에 대해서, 변환손실 <7dB와 Port별 격리도 >20dBc의 특성을 얻었다.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.11 no.4
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• pp.599-609
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• 2000

In this paper, sub-harmonically pumped single balanced resistive mixers are presented . Frequency bandwidth is selected for a Ku-band, which is 11.75-12.25GHz for RF, 5.375∼5.625 GHz for LO, and 1 GHz for IF signals. A rat-race hybrid is designed for the accomplishment of single balanced type. A low pass filter (LPF) with photonic band gap(PBG) structure is used for good conversion loss and unwanted harmonics suppression. Two types of mixers are suggested, which are one with no gate bias for no DC power consumption and the other with the IF amplifier for conversion gain. When a LO signal with the power of 6 dBm at 5.5 GHz is injected, a conversion loss of 12.17dB and a conversion gain of 7.83 dB are obtained for each mixer. For the both mixers , LO to RF isolation of 20 dB and LO to IF isolation of 60dB are obtained. With the RF power of -30dBm to -3dBm, the mixer shows linear characteristics region of IF. this mixer can be applied for Ku-band and other microwave communication systems.