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Aspirin-intolerant asthma (AIA) occurs from asthma exacerbation after exposure to aspirin. However, the underlying mechanisms of AIA occurrence are still unclear. The critical role of the solute carrier family 6 (neurotransmitter transporter, betaine/GABA) member 12 ( SLC6A12) gene in GABAergic transmission, which is associated with mucus production in asthma, makes it a candidate gene for AIA association study. Eight single nucleotide polymorphisms (SNPs) in SLC6A12 were genotyped in 163 aspirin-intolerant asthma (AIA) and 429 aspirin-tolerant asthma (ATA) patients of Korean ethnicity. Associations between polymorphisms of SLC6A12 and AIA were analysed using multivariate logistic analysis. Results showed that two polymorphisms and a haplotype in SLC6A12, rs499368 ( P= 0.005; Pcorr= 0.03), rs557881 (non-synonymous C10R, P= 0.007; Pcorr= 0.04), and SLC6A12_BL1_ht1 ( P= 0.009; Pcorr= 0.05) respectively, were significantly associated with AIA after multiple testing corrections. In addition, SNPs of SLC6A12 were significantly associated with the fall rate of FEV1 by aspirin provocation suggesting that SLC6A12 could affect reversibility of lung function abnormalities in AIA patients. Although these results are preliminary and future replications are needed to confirm these findings, this study showed evidence of association between variants in SLC6A12 and AIA occurrence among asthmatics in a Korean population. [ABSTRACT FROM AUTHOR]

A K-band double balanced mixer with 1.9 GHz ultra-wide bandwidth in a 0.18 μm CMOS technology is presented in this article. Baluns with slot pattern ground were applied to the proposed mixer for an ultra-wide band matching in RF and LO ports. The mixer down converts RF signals (23.1–25 GHz) to intermediate frequency signals (100 MHz–1 GHz) using a LO signal of 24.1 GHz. The mixer achieves a conversion gain of 3.4 dB with a RF signal of 24 GHz and a LO signal of 24.1 GHz. A 1 dB compression point of the mixer is -4 dBm, and the mixer consumes 20 mA current with a 1.8 V supply. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 232–235, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23991 [ABSTRACT FROM AUTHOR]

K-band single balanced mixer based on Gilbert type using 0.18 μm CMOS process is presented. For the circuit design, passive lumped elements such as a spiral inductor and a MIM capacitor are tested up 40 GHz. The designed mixer has a conversion gain of 2.3 dB and a P1dB of -3 dBm at 24 GHz. It dissipates the power of 30.6 mW with 1.8 V supply voltage and the overall size is 940 × 560 μm2. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 2134–2137, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21864 [ABSTRACT FROM AUTHOR]

A 60-GHz point-to-multipoint (P-MP) fiber-radio access link with data rate of 156 Mb/s is presented. For a compact system configuration, a small-size 60-GHz transceiver module with planar antennas is developed. A point-to-point (P-P) full-duplex fiber-optic configuration is extended to the scheme with multiple access points (APs) by using a tree coupler and a dense wavelength-division multiplexing (DWDM) multiplexer (MUX). The bit error rate (BER) performances of the 60-GHz fiber-radio access link are measured and compared. Furthermore, the effect of the extension to the scheme with multiple APs is evaluated. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 1219–1222, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21576 [ABSTRACT FROM AUTHOR]

A 60-GHz highly integrated small mobile terminal (MT) with integrated IF modem for a high-data-rate millimeter-wave radio-on-fiber communication system is proposed and inspected by the BER and PER experiment between the access point and mobile terminal. This terminal integrates a 60-GHz transmitter, receiver, and IF modem in one module. To minimize the volume of the mobile terminal, a microstrip line to rectangular waveguide transition, surface-mountable three-pole bandpass filter, successive detection-log video amplifier (SDLVA), and DPSK demodulator are used. As the performance of this mobile terminal is confirmed by the experiment results, it can access the high-data-rate (155.52 Mb/s) communication network in the picocell area. © 2005 Wiley Periodicals, Inc. Microwave Opt Technol Lett 44: 504–507, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20680 [ABSTRACT FROM AUTHOR]

A broadband planar integration and packaging of millimeter-wave circuits based on the integrated waveguide (IWG) and grounded coplanar waveguide (GCPW) transitions are proposed and demonstrated at the V-band. A novel wideband microstrip-line-to-IWG transition is proposed for the planar integration of the rectangular waveguide devices and the insertion loss per one transition is less than 0.1 dB from 43 to 73 GHz. A proposed surface-mountable filter has an insertion loss of 3 dB and a 3.3% bandwidth at a center frequency of 62 GHz. A broadband ribbon interconnection exhibits low loss of 0.2 dB from DC to 70 GHz and the insertion loss of a single microstrip-to-waveguide transition is less than 0.4 dB from 50 to 75 GHz. © 2005 Wiley Periodicals, Inc. Microwave Opt Technol Lett 44: 371–374, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20638 [ABSTRACT FROM AUTHOR]

This article reports on parasitic resonance effects of a ground plane with/without a ground opening underneath a signal via with an open stub on the performance of a vertical transition in a multilayer printed circuit board. An equivalent circuit model that accounts for the parasitic resonance due to the open stub inductance and the parasitic capacitance is developed and verified with the measured and simulated results. The fabricated transition exhibits a return loss better than about 10 dB and an insertion loss less than 1.9 dB up to 21.5 GHz. A good agreement is observed between measured and simulated results. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 2098–2100, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.25404 [ABSTRACT FROM AUTHOR]

Modification in tapered dielectric rod waveguide antenna is achieved by the implementation of step change in width in metallic waveguide transition. The proposed antenna has circular symmetric radiation pattern and gain about 15.3 dB with improved return loss and side lobes level at W-band. It has 10 dB beamwidth 53.2° and 48.6° in the E- and H-plane. Proposed antenna can be used for a millimeter wave quasi-optics feed array design in W-band imaging radiometer design. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 1221–1223, 2010; Published online in Wiley InterScience (www. interscience.wiley.com). DOI 10.1002/mop.25107 [ABSTRACT FROM AUTHOR]

A K-band frequency-modulated continuous wave phased array radar sensor with low-complexity receiver based on antenna switching is developed. The radar sensor comprises a single transmitter, a single transmitting antenna, four receiving antennas, a single-pole four-throw switch, and a single receiving channel. The receiving antennas are switched to the single receiving channel periodically. The performance of the developed radar sensor is evaluated experimentally on the basis of the angle and range information obtained by using a beamforming method. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 2848–2850, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24785 [ABSTRACT FROM AUTHOR]

A self-heterodyne diode mixer is proposed using thin film process based on alumina substrate at 60 GHz in conjunction with grounded coplanar waveguide transition. To down-convert both very low RF and LO signals received simultaneously from transmitter for self-heterodyne communication scheme, the proposed mixer adapted with the knee voltage bias condition of 0.65 [V] improves its mixing efficiency significantly. The designed SHM shows the conversion loss of -15.13 dB at RF and LO frequencies of 60.565 and 59.01 GHz, respectively, with both input powers of -15 dBm and it also can defines IMD free input dynamic range as -30 dBm. The measured return losses satisfies with more than 20 dB and 9 dB for RF/LO input and IF output port, respectively. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 13–15, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23959 [ABSTRACT FROM AUTHOR]

A novel cost-effective 60-GHz multi-chip module (MCM) is proposed and demonstrated. It is based on a low-cost multilayer printed wiring board (PWB) with a novel vertical transition and a single layer waveguide transition which enables the use of low-cost substrates with high dielectric loss for millimeter wave applications. The proposed MCM technology has been successfully applied to the packaging of a 60-GHz self-heterodyne mixer, and no substantial difference in the RF performance is observed with the packaging. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 2303–2305, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22719 [ABSTRACT FROM AUTHOR]

A small size 60-GHz full duplex transceiver module is developed for high data rate millimeter wave wireless access link. To realize a compact and low cost transceiver module, a planar millimeter wave bandpass filter is integrated by using broadband coplanar ribbon-bond interconnects in the module. The overall size of the module except input and output connectors is 50 mm × 75 mm × 23 mm. The measured RF output power is 16 dBm at 1-dB compression, with conversion gain of 30.6 dB and the conversion gain of the receiver being 23.4 dB. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 1212–1214, 2007; Published online in Wiley InterScience (www.interscience.wiley.com) DOI 10.1002/mop.22399 [ABSTRACT FROM AUTHOR]

A novel wideband uniplanar balanced subharmonic mixer is proposed and demonstrated. The mixer is based on the broadband tapered coplanar-waveguide (CPW) DC-block filter, and the in-phase and out-of-phase T-junctions are interconnected through a pair of quarter-wavelength slotlines. The fabricated subharmonic mixer has an RF bandwidth of more than one octave from 12 to 28 GHz with a conversion loss ranging from 8.5 to 12.5 dB for LO signals from 6.1 to 14.1 GHz with a power level of 9.5 dBm. The measured LO-to-RF, LO-to-IF, and RF-to-IF isolations are better than 15.5, 34, and 26.6 dB, respectively. © 2005 Wiley Periodicals, Inc. Microwave Opt Technol Lett 44: 508–510, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20681 [ABSTRACT FROM AUTHOR]

A novel wideband design of a microstrip line-to-integrated waveguide (IWG) transition is proposed and demonstrated at the V-band. The transition is implemented by using a quarter wavelength grounded coplanar waveguide (GCPW) transformer and two short-circuited slots. The measurements of the back-to-back connected transitions show an insertion loss of 0.7 dB and a return loss better than 15 dB with a bandwidth of 50% at 60 GHz. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 43: 21–23, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20362 [ABSTRACT FROM AUTHOR]