A multiband hybrid antenna with double layer structures for mobile devices

Abstract

fiber end under test and the fiber for detection were measured at 1.31-and 1.55-lm wavelengths using laser diodes (LDs), an optical power meter (OPM), and 3-dB coupler. When both the measured return losses at those two wavelengths were equal to $14.7 dB (from 14.7 to 15.7 dB in our experiments), the part of the fiber end under test could be identified as uneven [shown in Fig. 1 (a)]. If one of the two losses is not equal to $14.7 dB, the part can be identified as flat [shown in Fig. 1(b)]. Every part of the fiber end under test is covered under the scanning inspection areas and can be determined as uneven or flat. Consequently, the cleaved fiber end under test can be identified as successful or failed.In the experiments, the gap between the fiber for detection and the fiber under test was set to 40 lm, and each scanning distance was set to 10 lm. Typical experimental results are shown in Figure 4. In the figure, (a) and (c) show the flat parts of the inspected fiber end found using the proposed inspection method and (b) and (d) shows the SEM image of the flat end. The fiber ends in Figures 4(a) and 4(c) were found to be correctly and incorrectly cleaved, respectively. The experimental image with a correctly cleaved fiber end shows that the flat parts form a circle of about 140-lm diameter, which is a little larger than the actual 125-lm diameter fiber end. This is because a mode field area of light may radiate from the fiber end for detection. In contrast, the experimental results for the incorrectly cleaved fiber end show that half the fiber end parts are flat and the remainder is uneven. The results of the proposed inspection method and those from SEM observation are in good agreement. CONCLUSIONWe have proposed and demonstrated a novel fiber optic sensor for inspecting cleaved fiber end based on the Fabry-Perot interferometer. The sensor uses LDs, OPM, 3-dB coupler, and XY lateral adjustment stage. The images obtained for the inspected fiber ends were in good agreement with SEM observation images.ABSTRACT: The design of a hybrid antenna with double layer structures that allow multiband operation in the global system for mobile communications/digital communication systems/personal communication system/universal mobile telecommunications system and wireless local area network band bands is presented. By combining the resonant modes excited separately by the upper layer planar inverted-F antenna structure (0.88, 0.97, and 1.18 GHz) and lower layer monopole antenna type structure (1.38, 1.76, and 2.45 GHz), a dual-frequency operation with broadband characteristics can be observed, whereby the lower and upper frequency bands are operating between 0.86 and 1.00 GHz and between 1.15 and 2.63 GHz, respectively. From the experimental results, stable gain and good radiation efficiency are also exhibited within the bands of interest. V C 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:1543-1548, 2012; View this article online at wileyonlinelibrary.com.

A dual-band bandpass filter using integrated stepped impedance resonators

“…As an example mobile phone antennas use multiband filters to split the different frequency bands (Anguera, Andújar, Huynh Orlenius, & Picher Puente, 2013;Anguera, Andujar, & Garcia 2013;Sim, Chao, & He, 2012;Wong, 2003). This has led to extensive research in multiband BPF design with some dual-band BPF being reported in Feng and Shao (2006), Chang and Sun (2006), Chin and Yeh (2009), Zhang, Jiao, Wang, and Cao (2011), Zhang, Chen, Xue, and Li (2007), Luo, Qian, Ma, and Yeo (2010), Wu, Liang, Qin, and Li (2008) and Ghatak, Pal, Sarkar, and Poddar (2012).…”