A new antenna structure of internal long‐term evolution/wireless wide area network (698–960/1710–2690 MHz) laptop computer antenna formed by a coupled‐fed loop antenna connected with two branch radiators is presented. The two branch radiators consist of one longer strip and one shorter strip, both being efficient radiators and contributing multiresonant modes to greatly enhance the bandwidth of the antenna. The antenna's lower band is formed by a dual‐resonant mode mainly contributed by the longer branch strip, while the upper band is formed by three resonant modes contributed respectively by one higher‐order resonant mode of the longer branch strip, one resonant mode of the coupled‐fed loop antenna alone, and one resonant mode of the shorter branch strip. The antenna's lower and upper bands can therefore cover the desired 698–960 and 1710–2690 MHz bands, respectively. The proposed antenna is suitable to be mounted at the top shielding metal wall of the display ground of the laptop computer and occupies a small volume of 4 × 10 × 75 mm3 above the top shielding metal wall, which makes it promising to be embedded inside the casing of the laptop computer as an internal antenna. Details of the proposed antenna are studied in the paper. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52:2662–2667, 2010; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25556

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A monopole slot antenna printed on a small‐size FR4 substrate of 40 × 10 mm2 to provide two wide operating bands of 824–960 and 1710–2170 MHz for the wireless wide area network operation in the tablet computer is presented. The monopole slot is folded to achieve a compact configuration and is fed by a microstrip feedline loaded with a dual‐band band‐stop matching circuit on the same FR4 substrate. The band‐stop matching circuit can generate two separate parallel resonances at about 1050 and 2250 MHz, which respectively leads to additional resonance occurred nearby the resonant frequencies of the quarter‐wavelength slot mode at about 850 MHz and higher‐order slot mode at about 1900 MHz, thereby resulting in dual‐resonance excitation of the two excited slot modes to respectively cover the GSM850/900 and GSM1800/1900/UMTS operation. The bandwidth‐enhancement technique of using a dual‐band band‐stop matching circuit is reported for the first time in published articles, and its detailed operating principle is described in this study. Performances of the proposed antenna are also discussed. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:875–879, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26723

By optimizing the size of the hole-type asymmetric electrodes, a parabolic distribution of the electrical field lines has been simulated using COMSOL software in this article. Experimental measurement testifies the variable focusing characteristics of single PDLC cell and superimposing PDLC lenses within optical variable system. Equations are deduced to describe the characteristics of PDLC lens, the results show that the experiments are good agree with the simulation results. The PDLC lens has a fast response time as fast as less than 1 ms, which is advantage over other LC-based electrically controlled lens.

A compact reconfigurable coupled‐fed loop antenna of the mobile handset for multiband long‐term evolution (LTE)/wireless wide area network operation is presented. The antenna volume is 5 × 10 × 30 mm3 only, while the protruded ground has a width of 30 mm for mounting electronic components. The proposed antenna is consisted of a loop strip and a driven strip. Through the driven strip capacitively coupled to the loop strip, the antenna can generate a 0.25‐wavelength loop resonant mode to form the antenna's lower band to cover the GSM850/900 bands (824–960 MHz). The simple driven strip is also an efficient radiator to excite a resonant mode for the antenna's upper band to cover the GSM1800/1900/WCDMA Band1 bands (1710–2170 MHz). Moreover, when the chip inductor connected to the loop strip has been adjusted from 0 to 12 nH, the antenna's lower band can be shifted to lower frequency and cover the LTE Band17 band (704–746 MHz) and the antenna's upper band is not varied. This tunable technique can allow the loop antenna to cover more operating bands without adding the antenna volume. Detailed operating principle and performances of the proposed antenna are discussed in this article. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:2687–2691, 2014