935 resultados para microstrip patch antenna
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—This paper presents a textile patch antenna designed for WBAN applications at 2.45 GHz ISM band. The antenna uses denim as substrate and conductive fabric for the ground plane and radiator layers. The main purpose of this paper is to analyze the influence of typical deviation of denim properties and patch radiator dimensions on the performance of the antenna. The parameters considered in the analysis are the relative permittivity and thickness of denim and the width and length of the rectangular patch radiator. The dependence of the central operation frequency of the antenna on those parameters was studied using the antenna reflection coefficient obtained from EM simulations. Rules of thumb for one-shot design were derived and applied to design a rectangular patch antenna. An antenna prototype was fabricated and measured, demonstrating a 10 dB impedance band of 4.8 % centered at 2.45 GHz, in good agreement with simulated results
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Design and development of a photonic bandgap (PBG)-assisted shared-aperture dual-band orthogonal aperture-fed rectangular microstrip patch antenna element, which is suitable for a portable very small aperture terminal (VSAT), are presented in this paper. The dual-band dual-polarized antenna element achieves 21% input impedance bandwidth at the S- and C-bands. A comparison of the antenna with and without 2D PBG grids shows that the inclusion of PBG structures (PBGSs) improves the antenna performances. (c) 2005 Wiley Periodicals, Inc.
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The design, development, and testing of an X-band 137-element passive reflect away capable of incorporating active devices such as transistor amplifiers is presented. In order to avoid grating lobes in the radiation pattern, the interelement spacing is minimized using dual-feed aperture-coupled patch antenna elements. Far-field radiation pattern results are presented and compared with the predicted radiation patterns. (C) 1999 John Wiley & Sons, Inc.
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In this we have looked at the concept of introducing carbon nanotubes on the surfaces of the microstrip patch antennas. We examined the performance improvements in a patch antenna through finite difference time domain simulations to increase the efficiency of the antenna. The results suggest that carbon nanotubes lead to a higher gain due to their electrical properties. A high gain antenna with low power requirements resulted in achieving a higher overall bandwidth. The designed antenna's gain, bandwidth and directivity are analyzed before and after introducing carbon nanotubes. © 2013 IEEE.
Resumo:
Microstrip patch antennas are strong candidates for use in many wireless communications applications. This paper proposes the use of a patch antenna with two U-shaped slots to achieve dual band operation. A thick substrate helps broaden the individual bandwidths. The antenna is designed based on extensive IE3D simulation studies. A prototype antenna is fabricated and experimentally verified for the required performance.
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In this communication we present a novel polarization-agile microstrip antenna design. To dynamically change the polarization state, the radiating patch is fed by a tunable quasi-lumped coupler. The whole structure can be dynamically altered to radiate electromagnetic waves with vertical linear, horizontal linear, right-handed circular or left-handed circular polarization simply by changing the operating mode of the quasi-lumped coupler. Due to its topology the coupler is simply reconfigured by switching the bias of two varactor diodes via a very simple DC bias circuitry: no additional capacitors or inductors are required. A prototype is fabricated with a 0.762-mm-thick upper layer substrate for the radiating element and a 0.130-mm-thick layer substrate for the coupler circuit, both with the same dielectric material relative permittivity of 2.22. The simulated and measured scattering parameters, the axial ratio in circular radiation-mode and the cross-polarization level in linear mode, the gain and the radiation patterns are presented. The agile polarization capabilities of this new antenna, as demonstrated in this communication, underscore its suitability for modern wireless communications in a multi-path propagation environment.
Resumo:
Microstrip patch antennas are strong candidates for use in many wireless communications applications. This paper proposes the use of a patch antenna with two U-shaped slots to achieve dual band operation. A thick substrate helps broaden the individual bandwidths. The antenna is designed based on extensive IE3D simulation studies. A prototype antenna is fabricated and experimentally verified for the required performance.
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A circular miqrostrip antenna with a modified structure is presented. By adjusting the feed location along the circumference of the patch it is possible to match the antenna with a C microstrip line of any impedance. The impedance bandwidth and radiation characteristics are unaffected by this structural V modification.
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Two three-clement polarisation-agile active microstrip patch arrays have been developed . The radiating elements are square patches each with two transistors mounted on adjacent edges. The patches radiate orthogonal modes , the relative phase of which can be varied. Radiation patterns show good agreement with predictions from theory, in both linear and circular polarization, and no grating lobes were observed
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A new microstrip antenna element is described which exhibits polarization agility. This is achieved by employing a T-slot radiator which is driven by the edge fields of a balanced microstrip line. The balanced line can support two propagating modes. namely. an even mode and an odd mode, and be switching between these modes. the orthogonal arms of the T-slot radiator are separately excited thus forming orthogonally polarized radiated fields. A nucrostrip patch antenna, which displays polarization agility using the sane mechanism, is also described
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A novel dual frequency dual-polarized square microstrip patch antenna embedded with a slot is presented. The proposed antenna offers tunability of the frequency ratio between the two frequencies by adjusting the slot dimensions. This configuration also provides a size reduction up to -51 and 35% for the two modes as compared to a square micro strip patch antenna
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A novel H-shaped patch antenna suitable for wireless and satellite communications is presented. The new antenna has some advantages compared to conventional microstrip patch antennas, such as small size, a fewer number of modes, no harmonic resonance, and the provision of pure reactive impedances at its harmonics that can result in increasing the transmitter efficiency. The basic principles and design procedure are introduced. Two antennas at two different frequencies, 4 and 10 GHz, are designed, fabricated, and measured. The measured results show a good agreement with the predicted ones
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A novel technique fitr the bat dividth enhancement of conventional rectangular microstrip antenna is proposed in this paper. When a high permittivity dielectric resonator of suitable resonant frequency was loaded over the patch. the % bandwidth of the antenna was increased by more than five tunes without much affecting its gain and radiation performance. A much more improved bandwidth was obtained when the dielectric resonator was placed on the feedline. Experimental study shows a 2:1 VSWR bandwidth of more than 10% and excellent cross polarization performance with increased pass band and radiation coverage abnost the same as that of rectangular microstrip antenna
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An arrow-shaped microstrip antenna with a pair of narrow slots embedded near the non-radiating edges gives wide impedance bandwidth. The experimental and simulated (!E3D) results show that antenna bandwidth is -3.5 times that of a conventional patch with the added advantage of reduced antenna size. The radiation characteristics are found to he uniform throughout the operating band
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compact microstrip antenna integrated with an amplifier having an area reduction of 70%, compared to the standard circular microstrip patch antenna, is presented. The antenna also provides an enhanced gain of 10-dB more than its passive counter part. The measured 2:1 VSWR band width is -4% at 790 MHz, which is 2.5 times larger than that of the passive microstrip antenna