Abstract-This paper presents a multiband folded loop antenna for smart phone applications.The proposed antenna with a symmetric loop pattern generates four resonance modes in the design bands. The current distributions of the excited resonance modes are analyzed to confirm the mode characteristic. Using a pair of tuning elements near the feed port, the impedance bandwidth is broadened to cover GSM850/GSM900/DCS/PCS/UMTS bands. This research performed simulation by a high frequency structure simulator (HFSS) to optimally design the antenna, and a practical structure was constructed to test. The current study measured the antenna parameters including reflection coefficient, radiation characteristics, peak gain, and radiation efficiency to validate the proposed antenna.

of 0.9 GHz are 1.35 and 1.37 dBi, respectively. The simulated and measured gains at the frequency of 1.75 GHz are 3.71 and 3.84 dBi, respectively. The proposed antenna has relatively high gains, while the thickness of the antenna element is decreased. CONCLUSIONA newly compact and cable-fed patch antenna with dual-band performance has been proposed and implemented. By using a modified ground plane, a monopole radiator, and parasitic patches, the proposed small antenna can cover the GSM and DCS bands. In addition, the antenna has sufficiently high gain to be applied effectively in practical handset-antenna applications. ACKNOWLEDGMENTThis work was supported by the National Research Laboratory (NRL) of the Ministry of Science and Technology, Korea, under contract no. M1-0203-00-0015. The steadily growth of commercial interest in millimiter-wave and submillimiter wave applications, especially in wireless communications, security and sensory applications, and military and transport electronics, has provided a significant challenge to conventional microwave circuits and their design methodologies. Highperformance narrowband bandpass filters exhibiting low insertion loss, compact physical size, and low fabrication cost are important components to many microwave systems. Compact low-cost waveguide filters with high selectivity are therefore receiving particular interest [1,2]. Multilayer techniques are now well established and are being used extensively in MMICs, since passive components such as filters still suffer from large size when applied to MMICs. This allows a higher packing density for microwave circuits resulting in reduced size circuits, which are of great importance at these high frequencies. Resonators are fundamental filter elements that determine to a large extent the filter's electrical and physical properties. This paper presents a novel waveguide filter, based on a new proposed periodic-resonator structure. A resonator is designed, using the proposed topology, such that two arrayes of four metallic strips are used. An MMIC bandpass filter is also designed using this configuration. The filter consists of two resonator sections, whose lengths are chosen to be half the wavelength of the guide ( g / 2) at resonant frequency. The substrate is 1000-m wide and has a height of 430 m. The MMIC bandpass filter is designed and simulated using the commercial FEM software package HFSS™. CONFIGURATIONThe proposed resonant structure is shown in Figure 1. The structure consists of a block of dielectric, which is transversely inserted inside a rectangular waveguide housing with a ϭ 1696 m and b ϭ 127 m. Poly is used as a dielectric material with r ϭ 3.6. The periodic metallization strips are supported by the dielectric block. Finally, the whole structure is placed on top of GaAs substrate. The first and last sections consist of two metal strips, while the middle section has three strips. The number and size of the metallic strips in the first and last array mainly determine the insertion loss and bandwidth of the filt...

This article presents a band‐notched planar slot antenna presented to overcome interference with some already existing standards such as the IEEE802.11a and HYPERLAN/2 systems. The slot antenna, evolved from an elliptical aperture antenna, is fed by CPW with an elliptical tuning‐stub to achieve UWB characteristics. This slot antenna, using open‐end slits on the tuning stub or a pair of parasitic strips in the aperture, is then designed to reject the sub‐band between 5 and 6 GHz. Practical structures are fabricated and the measured results show that this antenna not only retains an ultrawide bandwidth but also has band‐rejection capability. In addition, its radiation pattern preserved the omni‐directional feature, meeting the UWB system requirements. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 1587–1592, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24343

Abstract-This paper presents a one-wavelength loop antenna fed by an inductively coupled loop for on-body applications. An equivalent circuit for the inductively coupled loop antenna is proposed to synthesize the antenna system with a microchip. The designed tag is printed on a PVC substrate and placed close to a four-layer stratified elliptical cylinder human model. The card-type tag measures 85.5 × 54 × 0.76 mm 3 and is suitable for use on a student ID card for a broad range of applications. The impedance bandwidth of the inductively coupled loop tag antenna is 60 MHz (880-940 MHz, 6.6%), which covers the operating UHF bands in U.S. and Taiwan. The measured reading distance ranges from 2.7 to 5.7 meters when placed at different positions on the chest of a human body in the open site.

Background:Angiogenic factors have an essential role in normal and pathologic angiogenesis. However, the clinical implication of angiogenic factor expression in myelodysplastic syndromes (MDS) remains unclear.Methods:In this study, we sought to investigate the prognostic impact of the expression of genes encoding angiopoietin-1 (Ang-1), Ang-2, the receptor Tie2, vascular endothelial growth factor-A (VEGF-A) and VEGF-C in the bone marrow (BM) in 208 patients with newly diagnosed primary MDS.Results:BM Ang-1 expression was significantly higher in MDS patients, especially those with higher-risk subtypes, than in normal controls. With a median follow-up time of 32.9 months, the disease transformed to acute leukaemia more frequently in the patients bearing higher Ang-1 expression than in those with lower expression (31.5% vs 18.6%, P=0.023). The MDS patients with higher Ang-1 expression had shorter overall survival than those with lower expression (median 20.8±4.5 months vs 63.3±17.8 months, P<0.001). Multivariate analyses showed that higher Ang-1 expression was an independent unfavourable prognostic factor for overall survival. There was no impact of the expression of other angiogenic factors on survival.Conclusion:BM Ang-1 expression may serve as a new biomarker to predict clinical outcome in MDS patients.