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Metamaterials are artificially constructed to have special electromagnetic properties not found in nature. In recent years, metamaterial is noted as a new kind of device, and the composite right/left-handed transmission lines have been proposed, which are characterized by antiparallel phase and group velocities and negative refractive index. The materials were termed as left-handed materials due to...
A novel compact dual-band antenna based on meander-line folded monopole is designed to cover UMTS frequency bands of I, III and VIII under the physical size constraint of 30 x 5.1 x 4 mm3 for UMTS/HSDPA-based data card applications. Good agreement between the numerical results and measured data is observed. The excellent measured gain performance at far-field chamber validates this useful design approach.
In this paper, the proposed small antenna, which using negative permittivity meta-material structure is designed, achieves wide Q more than calculated QL of chu limits. The equivalent circuit of proposed antenna is realized by Ansoft designer. The proposed small antenna is optimized by 3-D field simulation tool, CST MWS(micro wave studio).
In this paper, the miniaturization of a printed circular disc monopole antenna is investigated. It is shown that by halving the original antenna and adjusting the coplanar ground plane width, an even wider impedance bandwidth at the lower end can be obtained. Furthermore, a clear physical explanation is provided to illustrate the mechanism of this type of half circular disc antenna.
In this paper, a small antenna for the applications of GPS and DCS systems by utilizing the CPW feeding structure is proposed to provide the LP and CP radiation patterns. The CPW feeding structure possesses the advantages, such as low radiation loss, less dissipation, uniplanar structure without the ground plane, and easy integration with RF/microwave circuits, enabling a miniature hybrid or monolithic...
This paper presents a broadband omnidirectional vertically polarized antenna of only a one eighth wavelength associated to the lowest frequency. This antenna is composed of a conical monopole with metallic parasitic elements, a capacitive disk and a dielectric substrate placed above a square ground plane. This structure provides broadband performances and omnidirectional radiation patterns over the...
In this paper, a dual-band rejected design for cross monopole antenna is proposed and experimentally studied. To achieve wide and dual-band rejected operation, the proposed antenna consists of a UWB cross monopole antenna and the small h-shaped slots, producing dual band-rejected characteristics, maintaining wideband performance, and good omnidirectional radiation pattern. Details of the results for...
The investigation of user interaction presented in this paper focuses on the comparison between the free space and data mode diversity performance of a tri-band "stick" phone size prototype in the uniform 3D propagation environment. A state-of-the-art phantom hand from IndexSAR is used to hold the diversity prototype in the data mode position.
A printed monopole antenna for quad-band operation in the mobile phone has been proposed and studied. The antenna occupies a volume of 24.3 x 20 x 4 mm3 with a very low height as compared to others, yet it can cover two wide bands centred at about 925 MHz and 1920 MHz to realize GSM/DCS/PCS/UMTS operation. Good radiation characteristics of the antenna over the operating bands have also been observed...
Measured results of three typical internal mobile phone antennas held in talk-position by a real human operator are presented. Depending on exact placement of index finger, frequency band and type/position of radiator, total body losses ranging from 6-26 dB have been measured. In all cases, the absorption loss was much more significant than the mismatch loss. The monopole (off-ground) antenna was...
The butterfly-shaped monopole antenna proposed has provided good impedance matching across the UWB band of 3.1-10.6 GHz. The antenna design consists of a novel butterfly-shaped monopole above the ground plane. The antenna has two circular or elliptical wings which are connected to the two edges of a conducting plate. The wings may form different angles with the ground plane. The radiation patterns...
A modified small-size tapered monopole antenna is optimized for ultra wideband applications in co-design with the transceiver. Our optimization procedure aims at finding an antenna not only with low VSWR, but also miniaturizing the antenna at the same time. Our proposed optimization algorithm, real-coded compact genetic algorithm, RCCGA, has lowered the antenna area more than 48% compared to previous...
In this paper, we describe improved designs of a printed disc monopole antenna for UWB application, focusing on miniaturization of the disc radiator with the size of the ground fixed. In order to decrease the antenna size, an exponentially curved notch on the ground plane of the antenna was investigated, and the optimal design of the shape of notch verified. By appropriately adjusting the size of...
This paper presents several planar monopole antennas with a very compact size for UWB wireless applications. A systematic study of several topology feature was briefly reported. As a result two UWB antennas with a band rejection property with optimized parameters were proposed.This allows the antennas to cover the entire UWB frequency range, while not interfering with WLAN applications.The reported...
It is well known that a monopole antenna above a ground plane radiates an omni-directional beam around its axis. The height of this monopole can be reduced by using top-loading techniques. One such technique involves attaching a patch to the top of a monopole for use as a microwave antenna. In this case the structure is recognized as a low-profile, center-fed patch antenna. When the antenna height...
Wireless broadband communications such as UWB, WiMAX et. al. have been put into services in Japan, in order to realize high-speed transmission systems. Such a system enables to transmit movies from a person to the other person in the winking of an eye. To realize such wireless broadband communications, wideband antennas have been required. This paper describes the bandwidth limitations of ultra-wideband...
We have presented a dual spiral line loaded monopole antenna on a vertical ground plane. The antenna has a 152 MHz impedance bandwidth (820 ~ 972 MHz) for VSWR<2 at a central frequency of 896 MHz. The proposed antenna covers both the cellular and UHF RFID bands in Korea and is suitable as the internal antenna of a handheld transceiver unit because of its thin configuration, broad bandwidth, and...
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