covers the required bandwidth . Figure 3 studies the effects of the strip length L 2 of the C-shaped strip on the impedance matching of the proposed antenna. Measured results of the return loss for the case with various strip lengths of L 2 ϭ 5 to 7 mm are presented. It is seen that, by increasing the strip length L2, the antenna's lower band can be excited at lower frequencies. For the upper band, however, smaller effects of the strip length L 2 are seen. From the results obtained, the strip length L 2 for the printed meander antenna is selected to be 7 mm.The radiation patterns in the orthogonal x-y, y-z planes at 2.45, 5.25, and 5.8 GHz are shown in Figure 4, respectively. The measured results show good similar omnidirectional radiation in the azimuth plane (x-y plane), especially in the higher band, and conical radiation in the elevation plane (y-z plane). Figure 5 presents the measured peak gains of the proposed compact monopole antenna across two operating bands. The measured peak antenna gains for the operating frequencies across 2.4/5-GHz bands are measured to be 2.7 and 3.1 dBi, respectively. Gain variations of 2.2-2.7 dBi in the 2.4-GHz band and 2.0 -3.0 dBi in 5-GHz band are obtained. CONCLUSIONA novel multiband printed monopole antenna for WLAN communication has been proposed. By using a simple configuration, the prototype of the antenna has achieved satisfactory multiband performances, which obtains impedance bandwidths of 2.39 -2.52 and 5.12-7.12 GHz, the measured gains of 2.0 and 3.1 dBi, respectively. Also good similar omnidirectional radiation patterns in the azimuth plane in higher band are achieved. It is of low cost, light weight, and has a compact size of only 11.5 ϫ 8.5 mm 2 . These features are very suitable for multiband wireless applications. ABSTRACT: This article presents the design and fabrication of a short-pin dual-band E-shaped microstrip patch antenna for applicationin a 2.630 -2.655 GHz band satellite-DMB with a 5.725-5.825 GHz band wireless LAN. The prototype consist of a short-pin and E-shaped patch. To obtain sufficient bandwidth in VSWR Ͻ 2, an air layer is inserted between the ground plane and the substrate. A small short-pin patch that has a dual-band characteristic is used. Important design parameters are the slot's existence, length, the air-gap's height, the feed point's position, and the short-pin's existence and point position. From these optimized parameters, an E-shaped antenna is fabricated and measured. The measured results of the fabricated antenna are obtained individually at 200 and 700 MHz bandwidths in VSWR Ͻ 2 referenced to the center frequency, and the individual gain at 8.79 and 10.26 dBi. The experimental 3 dB beam width is shown to be broad across the passFigure 5 Measured antenna gains for the proposed antenna: (a) 2.4-GHz band; (b) 5-GHz band. [Color figure can be viewed in the online issue, which is available at www.interscience.wiley.com]

laser asynchronously are partially coherent, and this coherence property becomes weaker as the increase of the delay time. CONCLUSIONSOptical heterodyne technique has been used to investigate the frequency and temporal coherence properties of lightwaves emitted from a DBR laser asynchronously. Experiments demonstrate that lightwaves at different wavelengths and different emitting time are partially coherent, and the frequency coherence is stronger when the wavelengths are close and delay time is short. This is helpful for further understanding of lightwave properties of DBR laser and achieving narrow-linewidth microwave.

In this article, a mobile embedded antenna having tunable capacitance is proposed and the validity of the proposed solution was proved through design, fabrication, and measurement.The antenna can be applied to long‐term evolution (LTE) as well as DCS/PCS/WCDMA bands being currently used. Antennas for the 4G mobile service are required to expand its bandwidth so that it includes both LTE band and other service bands. However, it is hard to obtain low‐band characteristic due to the limited space for antenna in terminals. The proposed antenna consists of two planar inverted F antennas that are orthogonally arranged. Two radiators should be designed to have equal or enhanced isolation (S21) of lower than −15 dB. To meet this requirement, a varactor diode SMV2109 (skyworks corp.) was used to make the operation frequency of low‐band tunable. With the optimized parameters, the antenna was fabricated and measured and the results have been compared with the simulated result. The antenna satisfied with operation frequency and performance for both low‐band and high‐band, and measured performance of the antenna fabricated with optimized parameters is compared and analyzed with the simulation results. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:1141–1145, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27479

A compact five-pole UWB bandpass filter at P-band has been presented in this letter. The filter is designed with five shunt short-circuited stubs separated by connecting lines. The stubs and the connecting lines are folded to realize a compact size. Their physical dimensions are precisely determined by EM simulations. The filter is accurately designed and fabricated. Excellent agreements between the theoretical, simulated, and experimental responses are obtained and demonstrated.

In this paper, a clover‐shaped microstrip patch antenna for application under an Ultra‐Wide Band (3.1–10.6 GHz) is designed and fabricated. To obtain sufficient bandwidth when the Return Loss is < −10 dB, a partial ground plane and coaxial probe source is used. The measured bandwidth of the fabricated antenna is 8.25 GHz when VSWR <2. Referenced to the center frequency, the gain is 3.20–4.00 dBi. The experimental 3‐dB beam width (HPBW) in the azimuth and elevation are 55.35° and 62.27°, respectively. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 2111–2113, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21869