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ABSTRACT: In this work, approaches that aim to reduce SAR on human body were attempted. Algorithms were devised for automated antenna blockage assessment. These algorithms are used to determine the presence and location of obstacles in adjacent to a mobile device, A multi-antenna mock-up was fabricated to house several antennas at various locations on a palm-size device. According to the variation in the amount of coupling among antennas, the presence of an obstacle can be decided by the blockage assessment algorithm, which is built on neural network. The proposed algorithm was implemented in this work to differentiate a right/left hand holding scenario and hence verified its effectiveness.
Antenna Technology: Small Antennas and Novel Metamaterials, 2008. iWAT 2008. International Workshop on; 04/2008
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ABSTRACT: A novel beam switching antenna design is proposed in this work. This antenna uses a dipole as the fed and a cylindrical metal enclosure with a stack of circular slits is put around dipole. An array of RF switches made of pin diodes are placed across the slits. The antenna beam can be adjusted to the desired direction by changing on-off states of the switches, which in turn reconfigures the slot array orientation. The beam switching feature of the proposed antenna makes it an attractive low cost alternative to wireless communication systems that need to implement smart antennas in their base stations.
Antennas and Propagation Society International Symposium, 2007 IEEE; 07/2007
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Electromagnetics 06/2007; 27(5):253-262. · 0.79 Impact Factor
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ABSTRACT: A novel microstrip antenna applicable for multiband use is proposed in this work. The design was evolved from a conventional parallel stripline dipole with modifications in the dipole geometry and feeding structure. Those measures help introduce new resonant modes and increase bandwidths in the radiation spectrum. Fundamental antenna parameters including reflection coefficients, antenna gains, radiation patterns, and efficiency are measured. The results suggest that the proposed dipole provides roughly omni directional patterns at 1.8 to 2.4, 3.6, and 5.8 GHz bands with ∼0 dBi gain on the H-plane of the dipole. Such a planar antenna is of low cost and can be used on personal portable communication devices such as the smart phones to fulfill the multiband need of integrated mobile, Bluetooth, Wi-Fi, and WiMAX systems. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 237–241, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22081
Microwave and Optical Technology Letters 11/2006; 49(1):237 - 241. · 0.62 Impact Factor
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ABSTRACT: In this work, an LNA module is moved into a corner-truncated patch antenna, which is intended for GPS reception use. A cavity is formed within the substrate of the patch to accommodate the LNA module. The built-in LNA enhances the antenna reception capability without adding external circuits. Hence, the resulting patch has the same footprint and thickness as ordinary passive patches. Simulations and measurements on prototype antenna indicate that the built-in LNA module imposes limiting influences on the antenna properties, which can be corrected by rescaling the patch, and is hence an attractive option for making small antennas with large gains
Antennas and Propagation Society International Symposium 2006, IEEE; 08/2006
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ABSTRACT: We have developed a hybrid multiband antenna that integrates a loop antenna into the feed structure of a planar dipole. The planar dipole is tuned to handle GSM and 802.11b WLAN signals while the fundamental and higher order modes of the loop antenna can be used for 802.11a WLAN communications. We first introduce the basic design principles of the planar dipole, and then describe the techniques used to package a loop antenna with a planar dipole using a parallel stripline structure. Measured reflection coefficients comply with simulation predictions and exhibit low return loss in the desired communication bands. Measured radiation patterns reveal an omnidirectional coverage in the lower bands and a wide coverage in the higher band. Such an antenna configuration is suitable for portable devices that integrate multiple wireless communication systems.
Antennas and Propagation Society International Symposium, 2005 IEEE; 08/2005
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ABSTRACT: We discuss grounding issues specific to automotive applications.
We review the components of a typical automotive ground system, their
intended functions, and known limitations. Some sources of automotive
emissions are identified and the role of ground in mitigating these
emissions is discussed
Electromagnetic Compatibility, 1999 IEEE International Symposium on; 02/1999
