Current Issue : October - December Volume : 2015 Issue Number : 4 Articles : 8 Articles
A novel butterfly-shaped patch antenna for wireless communication is introduced in this paper. The antenna is designed for\nwideband wireless communications and radio-frequency identification (RFID) systems. Two symmetrical quasi-circular arms and\ntwo symmetrical round holes are incorporated into the patch of a microstrip antenna to expand its bandwidth.The diameter and\nposition of the circular slots are optimized to achieve a wide bandwidth. The validity of the design concept is demonstrated by\nmeans of a prototype having a bandwidth of about 40.1%. The return loss of the butterfly-shaped antenna is greater than 10 dB\nbetween 4.15 and 6.36GHz.The antenna can serve simultaneously most of the modern wireless communication standards....
In recent years development of wearable antennas for wireless communication system is a very important field of knowledge. Wearable antenna serves as element of clothes, whose purpose is performing tasks related to telecommunications such as tracking and navigation, remote computing and communication tasks related to public safety. The paper present the design of the wearable antenna made in micro strip technique working at a frequency of 5.5 GHz. Here Jeans textile is used as substrate for this antenna.The antenna is fed with inset feed.Here,examined the radiation characteristic, return loss and gain which are the critical parameters of wearable antenna....
A modular and efficient Gaussian beam (GB) analysis method, incorporating frame-based Gabor transformation, GB reflection,\nand a 3D GB diffraction technique, was developed to analyze both the reflectors and frequency selective surface (FSS) in quasioptical\n(QO) system. To validate this analysis method, a 3Ddual-channelQOsystem operating at 183 and 325GHz was designed and\ntested.The proposed QO system employs two-layer structure with a FSS of perforated hexagonal array transmitting the 325GHz\nsignal on the top layer while diverting the 183GHz signal to the bottom layer. Measured results of the system demonstrate that\nthe agreement can be achieved down to ?30 dB signal level for both channels in the far field pattern. The discrepancy between the\ncalculation and measurement is within 2 dB in the main beam region (2.5 times ?3 dB beamwidth), verifying the effectiveness and\naccuracy of the proposed method...
Oblique projection polarization filter (OPPF) can be applied as an effective approach for interference cancellation in high-frequency\nsurface wave radar (HFSWR) and other systems. In order to suppress the nonstationary ionosphere clutter further, a novel OPPF\nbased clutter suppressing scheme is proposed in this paper.The polarization and nonstationary characteristic of the clutter are taken\ninto account in the algorithms referred to as range-Doppler domain polarization suppression (RDDPS) and the range-time domain\npolarization suppression (RTDPS) method, respectively.The RDDPS is designed for weak ionosphere clutter and implemented in\nthe range-Doppler domain directly, whereas the RTDPS algorithm is designed to suppress the powerful ionosphere clutter with a\nmultisegment estimation and suppression scheme. About 15ââ?¬â??23 dB signal to interference ratio (SIR) improvement can be excepted\nwhen using the proposed method, whereas the targets can be more easily detected in the range-Doppler map. Experimental results\ndemonstrate that the scheme proposed is effective for nonstationary ionosphere clutter and is proven to be a practical interference\ncancellation technique for HFSWR....
A compact small-size coupled-fed antenna composed of an inverted L-shaped feeding strip and a shorting strip with double\nbranches for the WWAN/LTE bands operation in the internal smartphone application is presented. With the help of a novel\ndistributed LC resonant circuit, the proposed antenna can not only realize the miniaturization (15 Ã?â?? 28 Ã?â?? 4mm3) and multiband\nto cover 2G/3G/4G bands but also be tuned and optimized easily. The measured bandwidth with 3 : 1 VSWR is 163MHz (804ââ?¬â??\n967MHz) at the low-band and 1615MHz (1665ââ?¬â??3280MHz) at the high-band.What is more, the lowest measured efficiency in the\nwhole frequency band is more than 52% for practical applications.The operating principles and main parameters are detailed below.\nAnd successful simulation, fabrication, and measurement of the proposed antenna are shown in this paper....
A stepped cylindrical antenna with a higher-order mode ring patch for wideband conical radiation pattern is proposed. To\naccomplish a low profile with wideband conical radiation characteristics, a stepped cylindrical monopole and a TM41 higher-order\nmode ring patch with four shorting pins are utilized. The proposed antenna has a monopole-like radiation pattern with a wide\n10-dB return loss bandwidth of 11GHz (2GHzââ?¬â??13GHz). It can cover various wireless services, such as wireless broadband (WiBro;\n2.3GHzââ?¬â??2.39GHz), wireless local area networks (WLAN; 2.4GHzââ?¬â??2.484GHz, 5.15GHzââ?¬â??5.35GHz, and 5.725GHzââ?¬â??5.875GHz),\ndigital multimedia broadcasting (DMB; 2.63GHzââ?¬â??2.655GHz), and ultra wideband (UWB; 3.1GHzââ?¬â??10.6GHz). The antenna has a\nheight of only 0.12????0 at 2GHz....
This paper deals with the problem of sea clutter suppression for shipborne high frequency surface wave radar (HFSWR) based on\nthe joint domain localized (JDL) adaptive processing algorithm. The performance of the novel method is compared with 2D FFT\nplus digital beamforming (FFT-DBF) and orthogonal weight in different azimuths. The results based on simulated and real data\nshow that the novel method provides higher detection performance than others....
A novel algorithm is proposed for two-dimensional direction of arrival (2D-DOA) estimation with uniform rectangular array\nusing reduced-dimension propagator method (RD-PM). The proposed algorithm requires no eigenvalue decomposition of the\ncovariance matrix of the receive data and simplifies two-dimensional global searching in two-dimensional PM (2D-PM) to one dimensional\nlocal searching. The complexity of the proposed algorithm is much lower than that of 2D-PM. The angle estimation\nperformance of the proposed algorithm is better than that of estimation of signal parameters via rotational invariance techniques\n(ESPRIT) algorithm and conventional PM algorithms, also very close to 2D-PM.The angle estimation error and Cram�´er-Rao bound\n(CRB) are derived in this paper. Furthermore, the proposed algorithm can achieve automatically paired 2D-DOA estimation. The\nsimulation results verify the effectiveness of the algorithm....
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