The Experts below are selected from a list of 282 Experts worldwide ranked by ideXlab platform

Jin-koo Rhee - One of the best experts on this subject based on the ideXlab platform.

  • 3-D 94 GHz single balanced mixer for low Conversion Loss with ring coupler by DAML
    2009 34th International Conference on Infrared Millimeter and Terahertz Waves, 2009
    Co-Authors: Jin-koo Rhee, Yong-hyun Baek, Tae-jong Baek, Yeon-sik Chae, Mi-ra Kim
    Abstract:

    A 94 GHz single balanced mixer in 3-dimension was successfully fabricated. The GaAs-based low Loss transmission lines, dielectric-supported air-gapped microstrip lines (DAMLs), have been developed using surface micromachining technology, and the DAML-based hybrid ring coupler is successively fabricated. We have developed the high-performance 94 GHz single balanced active mixer using hybrid ring coupler with 70 nm gate length MHEMT. The mixer showed the Conversion Loss of 2.5 dB ~ 2.8 dB and isolation characteristics less than −30 dB, in the range of 93.65 GHz ~ 94.25 GHz. These results are the best performances demonstrated from a 94 GHz single balanced mixer utilizing GaAs-based HEMTs in terms of Conversion Loss as well as isolation characteristics.

  • Low Conversion Loss and high LO-RF isolation 94-GHz active down converter
    IEEE Transactions on Microwave Theory and Techniques, 2006
    Co-Authors: Bok-hyung Lee, Mun-kyo Lee, Byeong-ok Lim, Soon-koo Kim, Jin-koo Rhee, Jung-dong Park
    Abstract:

    We report a low Conversion Loss and high local oscillator (LO)-to-RF isolation 94-GHz monolithic-microwave integrated-circuit (MMIC) active down converter using 0.1-mum InGaAs/InAlAs/GaAs metamorphic high electron-mobility transistor (MHEMT). The fabricated MMIC active down converter employs a one-stage MHEMT amplifier in the RF port of the active down converter, thereby amplifying the RF signal and improving the LO-to-RF isolation by using an inherent S12 isolation characteristic. The fabricated MMIC active down converter shows an excellent Conversion Loss of 6.7 dB at an LO power of 10 dBm and high LO-to-RF isolations of 21 plusmn 0.5 dB in a frequency range from 93.7 to 94.3 GHz. High dc and RF performances of the MHEMT used for the active down converter are due to the optimized epitaxial and device structure, and a maximum transconductance of 760 mS/mm, a current gain cutoff frequency of 195 GHz, and a maximum oscillation frequency of 391 GHz were measured. A active down-converter module is assembled by mounting the active down-converter chip on a jig with low-Loss transition structure between the coplanar waveguide and waveguide. The fabricated active down-converter module shows a good Conversion Loss of 10.9 dB and a very high LO-to-RF isolation of 27.5 dB at 94.03 GHz

  • high switching performance 0 1 spl mu m metamorphic hemts for low Conversion Loss 94 ghz resistive mixers
    IEEE Electron Device Letters, 2005
    Co-Authors: Bok-hyung Lee, Mun-kyo Lee, Byeong-ok Lim, Soon-koo Kim, Sung-chan Kim, Hyung-moo Park, Dong-hoon Shin, Jin-koo Rhee
    Abstract:

    We report high switching performance of 0.1-/spl mu/m metamorphic high-electron mobility transistors (HEMTs) for microwave/millimeter-wave monolithic integrated circuit (MMIC) resistive mixer applications. Very low source/drain resistances and gate capacitances, which are 56 and 31% lower than those of conventional pseudomorphic HEMTs, are due to the optimized epitaxial and device structure. Based on these high-performance metamorphic HEMTs, a 94-GHz MMIC resistive mixer was designed and fabricated, and a very low Conversion Loss of 8.2 dB at a local oscillator power of 7 dBm was obtained. This is the best performing W-band resistive field-effect transistor mixer in terms of Conversion Loss utilizing GaAs-based HEMTs reported to date.

  • High switching performance 0.1-/spl mu/m metamorphic HEMTs for low Conversion Loss 94-GHz resistive mixers
    IEEE Electron Device Letters, 2005
    Co-Authors: Bok-hyung Lee, Mun-kyo Lee, Byeong-ok Lim, Soon-koo Kim, Sung-chan Kim, Hyung-moo Park, Dong-hoon Shin, Jin-koo Rhee
    Abstract:

    We report high switching performance of 0.1-/spl mu/m metamorphic high-electron mobility transistors (HEMTs) for microwave/millimeter-wave monolithic integrated circuit (MMIC) resistive mixer applications. Very low source/drain resistances and gate capacitances, which are 56 and 31% lower than those of conventional pseudomorphic HEMTs, are due to the optimized epitaxial and device structure. Based on these high-performance metamorphic HEMTs, a 94-GHz MMIC resistive mixer was designed and fabricated, and a very low Conversion Loss of 8.2 dB at a local oscillator power of 7 dBm was obtained. This is the best performing W-band resistive field-effect transistor mixer in terms of Conversion Loss utilizing GaAs-based HEMTs reported to date.

Bok-hyung Lee - One of the best experts on this subject based on the ideXlab platform.

  • Low Conversion Loss and high LO-RF isolation 94-GHz active down converter
    IEEE Transactions on Microwave Theory and Techniques, 2006
    Co-Authors: Bok-hyung Lee, Mun-kyo Lee, Byeong-ok Lim, Soon-koo Kim, Jin-koo Rhee, Jung-dong Park
    Abstract:

    We report a low Conversion Loss and high local oscillator (LO)-to-RF isolation 94-GHz monolithic-microwave integrated-circuit (MMIC) active down converter using 0.1-mum InGaAs/InAlAs/GaAs metamorphic high electron-mobility transistor (MHEMT). The fabricated MMIC active down converter employs a one-stage MHEMT amplifier in the RF port of the active down converter, thereby amplifying the RF signal and improving the LO-to-RF isolation by using an inherent S12 isolation characteristic. The fabricated MMIC active down converter shows an excellent Conversion Loss of 6.7 dB at an LO power of 10 dBm and high LO-to-RF isolations of 21 plusmn 0.5 dB in a frequency range from 93.7 to 94.3 GHz. High dc and RF performances of the MHEMT used for the active down converter are due to the optimized epitaxial and device structure, and a maximum transconductance of 760 mS/mm, a current gain cutoff frequency of 195 GHz, and a maximum oscillation frequency of 391 GHz were measured. A active down-converter module is assembled by mounting the active down-converter chip on a jig with low-Loss transition structure between the coplanar waveguide and waveguide. The fabricated active down-converter module shows a good Conversion Loss of 10.9 dB and a very high LO-to-RF isolation of 27.5 dB at 94.03 GHz

  • high switching performance 0 1 spl mu m metamorphic hemts for low Conversion Loss 94 ghz resistive mixers
    IEEE Electron Device Letters, 2005
    Co-Authors: Bok-hyung Lee, Mun-kyo Lee, Byeong-ok Lim, Soon-koo Kim, Sung-chan Kim, Hyung-moo Park, Dong-hoon Shin, Jin-koo Rhee
    Abstract:

    We report high switching performance of 0.1-/spl mu/m metamorphic high-electron mobility transistors (HEMTs) for microwave/millimeter-wave monolithic integrated circuit (MMIC) resistive mixer applications. Very low source/drain resistances and gate capacitances, which are 56 and 31% lower than those of conventional pseudomorphic HEMTs, are due to the optimized epitaxial and device structure. Based on these high-performance metamorphic HEMTs, a 94-GHz MMIC resistive mixer was designed and fabricated, and a very low Conversion Loss of 8.2 dB at a local oscillator power of 7 dBm was obtained. This is the best performing W-band resistive field-effect transistor mixer in terms of Conversion Loss utilizing GaAs-based HEMTs reported to date.

  • High switching performance 0.1-/spl mu/m metamorphic HEMTs for low Conversion Loss 94-GHz resistive mixers
    IEEE Electron Device Letters, 2005
    Co-Authors: Bok-hyung Lee, Mun-kyo Lee, Byeong-ok Lim, Soon-koo Kim, Sung-chan Kim, Hyung-moo Park, Dong-hoon Shin, Jin-koo Rhee
    Abstract:

    We report high switching performance of 0.1-/spl mu/m metamorphic high-electron mobility transistors (HEMTs) for microwave/millimeter-wave monolithic integrated circuit (MMIC) resistive mixer applications. Very low source/drain resistances and gate capacitances, which are 56 and 31% lower than those of conventional pseudomorphic HEMTs, are due to the optimized epitaxial and device structure. Based on these high-performance metamorphic HEMTs, a 94-GHz MMIC resistive mixer was designed and fabricated, and a very low Conversion Loss of 8.2 dB at a local oscillator power of 7 dBm was obtained. This is the best performing W-band resistive field-effect transistor mixer in terms of Conversion Loss utilizing GaAs-based HEMTs reported to date.

Hannu Tenhunen - One of the best experts on this subject based on the ideXlab platform.

  • A model for predicting sampler RF bandwidth and Conversion Loss
    1999 IEEE International Symposium on Circuits and Systems (ISCAS), 1999
    Co-Authors: P Eriksson, Hannu Tenhunen
    Abstract:

    A simple model for predicting the RF bandwidth and Conversion Loss of a sampler from a given sampling switch conductance function is presented. The model is valid for any conductance function and for any relation between sampling pulse width and sampler time constant. As an example, the model is here applied to the case with a linearly rising/falling sampling switch conductance function and differences between the sample-and-hold and track-and-hold modes of operation are studied.

  • ISCAS (6) - A model for predicting sampler RF bandwidth and Conversion Loss
    ISCAS'99. Proceedings of the 1999 IEEE International Symposium on Circuits and Systems VLSI (Cat. No.99CH36349), 1
    Co-Authors: P Eriksson, Hannu Tenhunen
    Abstract:

    A simple model for predicting the RF bandwidth and Conversion Loss of a sampler from a given sampling switch conductance function is presented. The model is valid for any conductance function and for any relation between sampling pulse width and sampler time constant. As an example, the model is here applied to the case with a linearly rising/falling sampling switch conductance function and differences between the sample-and-hold and track-and-hold modes of operation are studied.

Chi Hou Chan - One of the best experts on this subject based on the ideXlab platform.

  • Phase-Conjugated Arrays Using Low Conversion-Loss Resistive Phase-Conjugating Mixers and Stub-Loaded Patch Antennas
    IEEE Transactions on Microwave Theory and Techniques, 2008
    Co-Authors: Leung Chiu, Quan Xue, Chi Hou Chan
    Abstract:

    A 1-D four-element and 2-D eight-element phase-conjugated retrodirective arrays employing low Conversion-Loss resistive field-effect transistor mixers and stub-loaded patch elements are proposed. The mixer, systematically designed using a multi- harmonic loading technique, offers a low 5.2-dB Conversion Loss at a 4.5-dBm local oscillator power level. The stub-loaded patch element is a square patch with a capacitive open stub loaded at each of its four corners, leading to patch-size reduction, lower mutual coupling between adjacent elements, and broader beam width. With the same element spacing of half a free-space wavelength at 5.8 GHz, the mutual coupling is suppressed by 3.1 and 3.3 dB in the E- and if-planes, respectively, when compared to the conventional square patches. Within an angle of plusmn60deg normal to the arrays, distinct linearly polarized retrodirectivities in terms of pattern deformations are experimentally confirmed for both the H-plane of the 1-D array and both E- and H-planes for the 2-D array. Additionally, circularly polarized retrodirectivity are also experimentally confirmed for 2-D arrays.

  • A low-Conversion-Loss ring-hybrid mixer using TS-CMRC circuitry
    Microwave and Optical Technology Letters, 2004
    Co-Authors: Leung Chiu, Quan Xue, T.y. Yum, Chi Hou Chan
    Abstract:

    This paper presents a new fundamental single-balanced ring mixer incorporating T-shaped compact microstrip resonant cells (TS-CMRCs). The measured minimum single side-band (SSB) down-Conversion Loss of 3.3 dB is achieved for a 10.4-GHz RF signal and is better than 6 dB from 9.6–11.5 GHz with a 0.1-GHz IF. In addition, our working prototype demonstrates an excellent linearity response, in which the third-order intercept point (IP3) is 17 dBm with a spurious free-dynamic range of more than 55 dB. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 41: 206–209, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20095

  • Low Conversion-Loss fourth subharmonic mixers incorporating CMRC for millimeter-wave applications
    IEEE Transactions on Microwave Theory and Techniques, 2003
    Co-Authors: Quan Xue, Kam Man Shum, Chi Hou Chan
    Abstract:

    Low Conversion-Loss millimeter-wave fourth subharmonic (SH) mixer designs are proposed in this paper. A millimeter-wave (35 GHz) fourth SH mixer with four open/shorted stubs is designed and measured. The Conversion Loss is less than 15 dB within a 2.4-GHz bandwidth. The minimum Loss is 11.5 dB at the center frequency. By replacing two of the shunt stubs with a dual-frequency in-line stub consisting of newly developed compact microstrip resonating cells (CMRCs), the performance of the SH mixer is improved significantly. At 35 GHz, the Conversion Loss of this new fourth SH mixer is as low as 6.1 dB with a 3-dB bandwidth of 6 GHz. The Conversion Loss in the whole Ka-band (26.5-40 GHz) is less than 16 dB. The proposed fourth SH mixer incorporating with CMRCs provides a low-cost high-performance solution for RF subsystem design.

Byeong-ok Lim - One of the best experts on this subject based on the ideXlab platform.

  • Low Conversion Loss and high LO-RF isolation 94-GHz active down converter
    IEEE Transactions on Microwave Theory and Techniques, 2006
    Co-Authors: Bok-hyung Lee, Mun-kyo Lee, Byeong-ok Lim, Soon-koo Kim, Jin-koo Rhee, Jung-dong Park
    Abstract:

    We report a low Conversion Loss and high local oscillator (LO)-to-RF isolation 94-GHz monolithic-microwave integrated-circuit (MMIC) active down converter using 0.1-mum InGaAs/InAlAs/GaAs metamorphic high electron-mobility transistor (MHEMT). The fabricated MMIC active down converter employs a one-stage MHEMT amplifier in the RF port of the active down converter, thereby amplifying the RF signal and improving the LO-to-RF isolation by using an inherent S12 isolation characteristic. The fabricated MMIC active down converter shows an excellent Conversion Loss of 6.7 dB at an LO power of 10 dBm and high LO-to-RF isolations of 21 plusmn 0.5 dB in a frequency range from 93.7 to 94.3 GHz. High dc and RF performances of the MHEMT used for the active down converter are due to the optimized epitaxial and device structure, and a maximum transconductance of 760 mS/mm, a current gain cutoff frequency of 195 GHz, and a maximum oscillation frequency of 391 GHz were measured. A active down-converter module is assembled by mounting the active down-converter chip on a jig with low-Loss transition structure between the coplanar waveguide and waveguide. The fabricated active down-converter module shows a good Conversion Loss of 10.9 dB and a very high LO-to-RF isolation of 27.5 dB at 94.03 GHz

  • high switching performance 0 1 spl mu m metamorphic hemts for low Conversion Loss 94 ghz resistive mixers
    IEEE Electron Device Letters, 2005
    Co-Authors: Bok-hyung Lee, Mun-kyo Lee, Byeong-ok Lim, Soon-koo Kim, Sung-chan Kim, Hyung-moo Park, Dong-hoon Shin, Jin-koo Rhee
    Abstract:

    We report high switching performance of 0.1-/spl mu/m metamorphic high-electron mobility transistors (HEMTs) for microwave/millimeter-wave monolithic integrated circuit (MMIC) resistive mixer applications. Very low source/drain resistances and gate capacitances, which are 56 and 31% lower than those of conventional pseudomorphic HEMTs, are due to the optimized epitaxial and device structure. Based on these high-performance metamorphic HEMTs, a 94-GHz MMIC resistive mixer was designed and fabricated, and a very low Conversion Loss of 8.2 dB at a local oscillator power of 7 dBm was obtained. This is the best performing W-band resistive field-effect transistor mixer in terms of Conversion Loss utilizing GaAs-based HEMTs reported to date.

  • High switching performance 0.1-/spl mu/m metamorphic HEMTs for low Conversion Loss 94-GHz resistive mixers
    IEEE Electron Device Letters, 2005
    Co-Authors: Bok-hyung Lee, Mun-kyo Lee, Byeong-ok Lim, Soon-koo Kim, Sung-chan Kim, Hyung-moo Park, Dong-hoon Shin, Jin-koo Rhee
    Abstract:

    We report high switching performance of 0.1-/spl mu/m metamorphic high-electron mobility transistors (HEMTs) for microwave/millimeter-wave monolithic integrated circuit (MMIC) resistive mixer applications. Very low source/drain resistances and gate capacitances, which are 56 and 31% lower than those of conventional pseudomorphic HEMTs, are due to the optimized epitaxial and device structure. Based on these high-performance metamorphic HEMTs, a 94-GHz MMIC resistive mixer was designed and fabricated, and a very low Conversion Loss of 8.2 dB at a local oscillator power of 7 dBm was obtained. This is the best performing W-band resistive field-effect transistor mixer in terms of Conversion Loss utilizing GaAs-based HEMTs reported to date.