• Title, Summary, Keyword: mixer

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The Design of a Sub-Harmonic Dual-Gate FET Mixer

  • Kim, Jeongpyo;Lee, Hyok;Park, Jaehoon
    • Journal of electromagnetic engineering and science
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    • v.3 no.1
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    • pp.1-6
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    • 2003
  • In this paper, a sub-harmonic dual-gate FET mixer is suggested to improve the isolation characteristic between LO and RF ports of an unbalanced mixer. The mixer was designed by using single-gate FET cascode structure and driven by the second harmonic component of LO signal. A dual-gate FET mixer has good isolation characteristic since RF and LO signals are injected into gatel and gate2, respectively. In addition, the isolation characteristic of a sub-harmonic mixer is better than that of a fundamental mixer due to the large frequency separation between the LO and RF frequencies. As RF power was -30 ㏈m and LO power was 0 ㏈m, the designed mixer yielded the -47.17 ㏈m LO-to-RF leakage power level, 10 ㏈ conversion gain, -2.5 ㏈m OIP3, -12.5 ㏈m IIP3 and -1 ㏈m 1 ㏈ gain compression point. Since the LO-to-RF leakage power level of the designed mixer is as good as that of a double-balanced mixer, the sub-harmonic dual-gate FET mixer can be utilized instead.

Design of Double-Conversion Down Mixer Using Single Half-LO Frequency at 2.3 GHz (2.3 GHz 대역에서 단일 Half-LO 주파수를 이용한 Double-Conversion Down Mixer 설계)

  • Kim Min-Seok;Moon Ju-Young;Yun Sang-Won
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.17 no.8
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    • pp.719-724
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    • 2006
  • In this paper, we designed the double conversion down mixer by using Half-LO frequency in 2.3 GHz band. The IF frequency is obtained by supplying two LO frequencies to HEMT in both gate type and resistive type. The proposed mixer uses Half-LO frequency the same way as conventional sub-harmonic mixers. However the proposed one uses fundamental component of Half-LO frequency in first stage instead of using second harmonic components of Half-LO frequency, and the IF frequency is obtained by resistive type mixer in second stage, thereby the proposed mixer can improve linearity in comparison with conventional active mixer. We can verify that the proposed mixer has an conversion loss of 5dBm and IIP3 of 16.25dBm by using 10 dBm Power.

The design of 85GHz-115Ghz band SIS mixer for the observing cosmic radio waves (85GHz-115Ghz 대 우주전파 관측용 초전도체 믹서 설계)

  • 한석태;김효령;이창훈;박종애;정현수;김광동;김태성;박동철
    • Journal of the Korean Institute of Telematics and Electronics A
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    • v.33A no.6
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    • pp.90-98
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    • 1996
  • We have evaluated the theoretical conversion loss and noise temperature of mixer using the quantum mixer theory and the method to determine the embedding impedance of waveguide-type mixer mount. At fixed backshort position of the mixer, the calculated SSB mixer conversion loss and mixer noise temperature are 5 dB and 10K within frequency range form 85 GHz to 115 GHz, respectively. The SIS mixer has been developed by using through on the calculated rsutls to observe cosmic radio waves. SIS junction of mixer is Nb/Al-AlOx/Nb and it consists of four series array. Area of each of junction is about 2.5${\mu}m^{2}$. The average receiver noise temperature of manufactured receiver with this mixer is about 30 K(DSB). The receiver noise temperature is much lower than that of receiver with a mixer using mechanical tuning backshort.

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Effect of static mixer geometry on flow mixing and pressure drop in marine SCR applications

  • Park, Taewha;Sung, Yonmo;Kim, Taekyung;Lee, Inwon;Choi, Gyungmin;Kim, Duckjool
    • International Journal of Naval Architecture and Ocean Engineering
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    • v.6 no.1
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    • pp.27-38
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    • 2014
  • Flow mixing and pressure drop characteristics for marine selective catalytic reduction applications were investigated numerically to develop an efficient static mixer. Two different mixers, line- and swirl-type, were considered. The effect of vane angles on the relative intensity, uniformity index, and pressure drop was investigated in a swirl-type mixer; these parameters are dramatically affected by the mixer geometry. The presence of a mixer, regardless of the mixer type, led to an improvement of approximately 20% in the mixing performance behind the mixer in comparison to not having a mixer. In particular, there was a tradeoff relationship between the uniformity and the pressure drop. Considering the mixing performance and the pressure drop, the swirl-type mixer was more suitable than the line-type mixer in this study.

Implement of Broadband Resistive Mixer for X-band FMCW Radar (X밴드 FMCW 레이더용 광대역 저항성 주파수 혼합기 구현)

  • Park, Dong-Kook;Han, Tae-Kyoung
    • Journal of Advanced Marine Engineering and Technology
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    • v.31 no.8
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    • pp.970-974
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    • 2007
  • A mixer is a key component in the wireless communication systems. In this paper, we design a mixer which is used in a frequency modulated continuous wave(FMCW) radar system. The frequency sweep range of the radar is from 10 GHz to 11 GHz. The transmitted and received signals of the FMCW radar are applied to LO and RF ports of the mixer, respectively, but the frequency difference between the two signals, which is called "a beat frequency" is under a few KHz and depending on the distance to target. Thus the isolation between the LO and RF ports is very important factor to design this mixer. In this paper we propose a single balanced resistive mixer using GaAs MESFET for this application. We first design a single-ended type resistive mixer using a simulation tool, then design a balanced type to increase the LO-to-RF isolation of the mixer. We fabricated the mixer on the substrate of dielectric constant 10 and thickness 0.635 mm. The measured results show that the isolation and conversion loss of the mixer over the frequency band is 20dB and 10.5dB, respectively. The LO input power for operating the proposed mixer is +3dBm, which is lower than a general conventional mixer's LO power. The 1 dB compression point is 6dBm.

A High Performance Harmonic Mixer Using a plastic packaged device

  • Kim, Jae-Hyun;Go, Min-Ho;Park, Hyo-Dal;Shin, Hyun-Sik
    • The Journal of the Korea institute of electronic communication sciences
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    • v.2 no.1
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    • pp.1-9
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    • 2007
  • In this paper, a third-order harmonic mixer is designed using frequency multiplier theory for the Ka-band. The gate bias voltage is selected by frequency multiplier theory to maximize the third-order harmonic element ofthe fundamental LO frequency in the proposed mixer. The designed mixer has a gate mixer structure composed of a gate terminal input for the fundamental local signal ($f_{LO}$), RF signal (${RF}$) and a drain terminal output for the harmonic frequency ($3f_{LO}-f_{RF}$) respectively. The Ka-band harmonic mixer is designed and fabricated using a commercial GaAs MESFET device with a plastic package. The proposed mixer will provide a solution for the problems found in the high cost, complex circuitry in a conventional Ka-band mixer. The 33.5 GHz harmonic mixer has a -10 dB conversion gain by pumping 11.5 GHz LO with a +5 dBm level.

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The Stress Analysis of Planetary Gear System of Mixer Reducer for Concrete Mixer Truck

  • Bae, Myung Ho;Bae, Tae Yeol;Cho, Yon Sang;Son, Ho Yeon;Kim, Dang Ju
    • Journal of Drive and Control
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    • v.12 no.4
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    • pp.77-81
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    • 2015
  • In general, the gears of mixer reducer for concrete mixer truck make use of the differential type planetary gear system to rotate mixer drum smoothly on the initial conditions. The planetary gear system is very important part of mixer reducer for concrete mixer truck because of strength problem. In the present study, calculating the gear specifications and analyzing the gear bending & compressive stresses of the differential planetary gear system for mixer reducer are necessary to analyze gear bending and compressive stresses confidently, for optimal design of the planetary gear system in respect to cost and reliability. As a result, analyzing actual gear bending and compressive stresses of the planetary gear system using Lewes & Hertz equation and verifying the calculated specifications of the planetary gear system, evaluate the results with the data of allowable bending and compressive stress from the Stress-No. of cycles curves of gears.

Research on Fourth Harmonic Mixer at W Band in the Imaging System

  • Xiang, Bo;Dou, Wenbin;He, Minmin;Wang, Zongxin
    • Journal of electromagnetic engineering and science
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    • v.10 no.4
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    • pp.316-321
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    • 2010
  • This paper presents a novel fourth harmonic mixer with new structure. The traditional 3-ports fourth harmonic mixer and the novel fourth harmonic mixer are designed by ADS, HFSS and CST simulator. The mixers have been fabricated and tested. The size of the traditional 3-ports fourth harmonic mixer is $12{\times}15$ mm, and the best conversion loss is 18.7 dB according to the measurement. Since the traditional 3-port mixer size is too large to be ranked, we design a novel fourth harmonic mixer for imaging system. The width of the mixing module in the novel fourth harmonic mixer is only 3.65 mm, and this size is fully capable to meet the mixer unit space which is not greater than 5 mm. The simulation result shows that the mixer has good performance, and the experiment result shows that the best conversion loss of the novel fourth harmonic mixer is 16.3 dB at RF signal of 91.3 GHz.

Fabrication and Mixing Characteristics of a Micro-Mixer with a Quasi-Active Rotor (준 능동형 로터를 이용한 마이크로 혼합기의 제작 및 혼합특성)

  • Kim, Young-Dae;Lee, Jong-Kwang;Kwon, Se-Jin
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.33 no.4
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    • pp.417-424
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    • 2009
  • A micro-mixer with a quasi-active rotor was fabricated, and mixing characteristics were evaluated. The proposed micro-mixer combines an active type micro-mixer with a passive type micro-mixer. The micro-rotor, which is a moving part of an active type micro-mixer, is added in a micro-chamber of a passive type vortex micro-mixer. The rotor rotated by inflows tangent to a chamber, causing strong perturbations. The micro-mixers were fabricated using photosensitive glass. Mixing efficiency of the micro-mixers was measured using an image analysis method. Mixing efficiency and characteristics of the micro-rotor mixer were compared with the vortex micro-mixer without a rotor. Mixing efficiency was reduced as Reynolds number increased at a low Reynolds number due to decrease of residence time. Mixing efficiency at higher Reynolds number, on the other hand, was improved even though residence time decreased since the contact surface between fluids increased by twisted flow. The perturbation induced by rotating rotor at greater than Re 200 improved the efficiency of the rotor mixer.

A Design of MMIC Mixer for I/Q Demodulator of Non-contact Near Field Microwave Probing System (비접촉 마이크로웨이브 프루브 시스템의 I/Q Demodulator를 위한 MMIC Mixer의 설계)

  • Ryu, Keun-Kwan;Kim, Sung-Chan
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.16 no.5
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    • pp.1023-1028
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    • 2012
  • A MMIC (Monolithic Microwave Integrated Circuit) mixer chip using the Schottky diode of an GaAs p-HEMT process has been developed for the I/Q demodulator of non-contact near field microwave probing system. A single balanced mixer type is adopted to achieve simple structure of the I/Q demodulator. A quadrature hybrid coupler and a quarter wavelength transmission line for 180 degree hybrid are realized with lumped elements of MIM capacitor and spiral inductor to reduce the mixer chip size. According to the on-wafer measurement, this MMIC mixer covers RF and LO frequencies of 1650MHz to 2050MHz with flat conversion loss. The MMIC mixer with miniature size of $2.5mm{\times}1.7mm$ demonstrates conversion loss below 12dB for both variations of RF and LO frequencies, LO-to-IF isolation above 43dB and RF-to-IF isolation above 23dB, respectively.