A new square planar monopole antenna capable of providing a very wide impedance bandwidth of larger than 10 GHz is presented. The ultra‐wideband property for the proposed antenna is achieved by using a new impedance‐matching technique of cutting a pair of notches at the two lower corners of the square planar monopole. With suitable dimensions of the notches chosen, the impedance bandwidth of the proposed antenna can be greatly enhanced to be larger than four times that of a corresponding simple square planar monopole antenna (about 10.7 versus 2.5 GHz in this study). A constructed prototype with an ultra‐wideband property covering the 2–11‐GHz band for IEEE 802.16a operation is presented and discussed. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 42: 463–466, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20337

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User's hand effects on an electromagnetic‐compatible (EMC) internal dual‐band mobile phone antenna for GSM/DCS operation are studied. The EMC internal antenna can be placed in direct contact with nearby conducting elements, without degradation in the antenna performances. Experimental and simulation studies are conducted to analyze the user's hand effects on this EMC antenna. Obtained results indicate that the user's hand affects not only the impedance matching of the antenna, but also the radiation characteristics including radiation patterns and efficiency. Effects of different positions of the user's hand holding the mobile phone are also analyzed and discussed. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 1563–1569, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21699

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a novel multi-function and miniaturization antenna design concept was presented in this paper. The proposed antenna has a small volume with dimension 22.2 mm(L) x 7.2 mm(W) x 2.6 mm(T). Antenna height is only less than 3 mm that is low profile can easily built in any kind of wireless device application. Antenna is printed on RF4 and then packaged as an IC type antenna, like a standard SMD component, that can effectively save development lead time and cost. The proposed antenna uses a proper matching circuit to fine-tune antenna resonant mode for multi-function operating. Now, we had successfully implemented this IC antenna in USB dongle card and mobile phone for cellular band operating, and WLAN, GPS operating in notebook.

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other two. Considering that radiation fog has the smallest particlesize distribution, our results should stand for this type of fog as well. Although we do not know the exact particle-size distribution of the fog in the measured link, the upslope fog is similar in formation to the advection fog; therefore, we also believe that, for this type of fog, the performance of the far-IR link should not be worse than those of the other two. Of course, present-day commercial technology still benefits shorter wavelengths, mostly due to the availability of low-cost sources and detectors. However, new technologies can produce competing devices for the far-IR window; thus our results demonstrate that it is worth working in the development of appropriate devices and systems because the optical channel indeed performs better at long wavelengths in most cases. ACKNOWLEDGMENTSThis work was supported by the Research and Development Center of Ericsson Telecomunicações S/A, Brazil, and C. P. Colvero acknowledges scholarship support from the Brazilian Agency CNPq. The authors acknowledge the Brazilian state companies TVE Brasil and Furnas Centrais Elétricas S/A for allowing the installation of the transmitters and receivers within their facilities. INTRODUCTIONDue to the recent successful deployment of wireless local area networks (WLANs) in numerous hotspots, it has become promising to integrate cellular and WLAN networks to provide ubiquitous or seamless data services for users [1, 2]. For this kind of integrated cellular/WLAN network application, it is expected that mobile phones or PDA phones capable of dual-network operation will become popular in the near future. For this promising application, many of the dual-network mobile or PDA phones are generally equipped with two antennas, one for cellular operation and another for WLAN operation. In this case, since there are limited spaces available inside the portable devices, isolation between the two antennas has become a critical issue. However, very little related information is available in the open literature.Recently, a study on the isolation between two promising internal antennas-one GSM/DCS (890 -960 MHz/1710 -1880 MHz) antenna and one 2.4-GHz (2400 -2484 MHz) WLAN antenna [3]-for a dual-network PDA phone has been presented [4]. The results have shown that with the GSM/DCS antenna fixed at the top edge of the system circuit board, optimized or nearoptimized isolation is achieved when the WLAN antenna is placed near the bottom edge of the system circuit board. In this study, the maximum isolation S 21 values over the GSM, DCS, and WLAN bands are less than Ϫ33.6, Ϫ27.9, and Ϫ33.0 dB, respectively, which are quite good for practical applications [4]. However, in this case, the two antennas need to be separated by a relatively large distance. In this paper, we present an isolation study that considers two promising internal GSM/DCS and WLAN antennas printed and integrated on a dielectric substrate. In the study, both of the GSM/DCS and WLAN antennas are printed PIFAs of compact...

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