Showing papers on "Metamaterial antenna published in 2001"
TL;DR: In this article, a compact circular-polarization (CP) operation of the square microstrip antenna with four slits and a pair of truncated corners is proposed and investigated.
Abstract: A novel compact circular-polarization (CP) operation of the square microstrip antenna with four slits and a pair of truncated corners is proposed and investigated. Experimental results show that the proposed compact CP design can have an antenna-size reduction of about 36% as compared to the conventional corner-truncated square microstrip antenna at a given operating frequency. Also, the required size of the truncated corners for CP operation is much greater than that for the conventional CP design using a simple square microstrip patch, providing a relaxed manufacturing tolerance for the proposed compact CP design. Details of the experimental results are presented and discussed.
253 citations
TL;DR: This paper describes the design and testing of a prototype dual-band dual-polarized planar array operating at L- and X-bands, featuring low mass, high efficiency, and limited beam scanning.
Abstract: This paper describes the design and testing of a prototype dual-band dual-polarized planar array operating at L- and X-bands. The primary objectives were to develop new antenna technology with dual-band and dual-polarization capability in a shared aperture, featuring low mass, high efficiency, and limited beam scanning. The design of a prototype planar microstrip array of 2/spl times/2 L-band elements interleaved with an array of 12/spl times/16 X-band elements that meets these requirements is discussed in detail and measured results are presented. The array is modular in form and can easily be scaled to larger aperture sizes.
200 citations
TL;DR: In this paper, the impedance of a rectangular patch antenna fed by an inset microstrip transmission line was measured for various feed positions and the dependence found was then compared to theoretical predictions both for this geometry and for the similar case of an INSET coaxial probe feed.
Abstract: The impedance of a rectangular patch antenna fed by an inset microstrip transmission line was measured for various feed positions. The dependence found was then compared to theoretical predictions both for this geometry and for the similar case of an inset coaxial probe feed.
125 citations
TL;DR: A novel configuration of a U-shaped dual-frequency single feeding port planar inverted-F microstrip antenna for mobile communication applications in both the GSM and DCS 1800 systems operated at 0.9 and 1.8 GHz is presented.
Abstract: We present a novel configuration of a U-shaped dual-frequency single feeding port planar inverted-F microstrip antenna for mobile communication applications in both the GSM and DCS 1800 systems operated at 0.9 and 1.8 GHz, respectively. Starting from an initial design derived from an empiric approximation and transmission line model for a standard rectangular microstrip antenna, we analyze, tune, and optimize the electric performance of the antenna and its dimensions by means of the generalized nonuniform finite-difference time-domain (NU-FDTD) Maxwell's solver.
24 citations
TL;DR: In this article, it is shown that a power-divider can be made from a two-section transmission line transformer in each branch, and it is economical to have one base station antenna array for the dual-frequency operation of the mobile phones.
Abstract: It is economical to have one base station antenna array for the dual-frequency operation of the mobile phones. From transmission line theory, it is shown that a power-divider can be made simply from a two-section transmission line transformer in each branch.
20 citations
03 Dec 2001
TL;DR: In this paper, an experimental study of the harmonic resonance suppression of a square microstrip antenna fed by using a 50 /spl Omega/ inset microstrip line with an open-circuited tuning stub is presented.
Abstract: This paper presents an experimental study of the harmonic resonance suppression of a square microstrip antenna fed by using a 50 /spl Omega/ inset microstrip line with an open-circuited tuning stub. The antenna studied is operated at the 1.8 GHz band. By choosing the open-circuited tuning stub to be about 0.125 guided wavelength of the fundamental frequency and placing the tuning stub at a suitable position away from the feed point, the possible resonance of the microstrip antenna at the second harmonic frequency can be suppressed. The obtained experimental results are presented and discussed.
17 citations
TL;DR: A modified cavity model to compute the resonance frequency of a rectangular patch antenna on a thick polytetrafluoroethylene substrate with maximum deviation of 2% against experimental results is presented in this paper.
Abstract: A modified cavity model to compute the resonance frequency of a rectangular patch antenna on a thick polytetrafluoroethylene substrate (0037/spl lambda//sub g/ 0229/spl lambda//sub g/) with maximum deviation of 2% against experimental results is presented This accuracy is achieved by accounting for the effect of anisotropy and total losses on the resonance frequency All other models, including the method of moments (MOM)-based Ensemble, compute resonance frequency with error between 4 and 36%
10 citations
08 Jul 2001
TL;DR: A dual band dual polarisation microstrip patch antenna element using a square patch with slots along and near the four edges is used together with aperture coupled microstrip line feeding.
Abstract: A dual band dual polarisation microstrip patch antenna element is presented. A square patch with slots along and near the four edges is used together with aperture coupled microstrip line feeding. The structure is designed for GSM 1800 and Bluetooth applications. A prototype is designed and tested. Good agreement is obtained between simulation and experimental results.
4 citations
08 Jul 2001
TL;DR: In this paper, a microstrip patch at the focal point of a small lens of only three wavelengths in diameter was used to focus the electromagnetic energy in spite of being electrically small, but the focal region is quite spread out and the focal length is different from that predicted by geometrical optics.
Abstract: In a phased array with limited-scan capability, the radiating element spacing is larger than one half wavelength and the element gain is higher than its full-scan counterpart to avoid grating lobes. This paper presents a new high-gain element made of a microstrip patch at the focal point of a small lens of only three wavelengths in diameter. Simulations showed that the lens still focuses the electromagnetic energy in spite of being electrically small. However, the focal region is quite spread out and the focal length is different from that predicted by geometrical optics. Fabrication and tests of a single element and a four-element array showed good agreement with theory. One application for a limited-scan array is an electronic tracking antenna for a fixed satcom terminal looking at a geosynchronous satellite stabilized in azimuth but not in elevation, as is often the case with military satellites.
3 citations
03 Dec 2001
TL;DR: In this paper, the authors show that the power splitters can be made from a two-section transmission-line transformer in each branch and analyzed by the transmission line theory, which can be used for beamforming matching networks.
Abstract: In antenna arrays of dual-frequency wireless systems, the beam-forming matching-network may require power splitters that give equal phases at the two outputs, but different unequal power splits at different frequencies. This paper shows that the power splitters can simply be made from a two-section transmission-line transformer in each branch and analyzed by the transmission-line theory.
3 citations
03 Dec 2001
TL;DR: In this article, a single-feed CP design of compact triangular microstrip antennas with a triangular slot has been proposed, which can have good CP radiation characteristics with a reduced antenna size of about 30% compared to the regular-size CP design using a simple triangular patch.
Abstract: The single-feed CP designs of compact triangular microstrip antennas with a triangular slot have been demonstrated. Simply by inserting a narrow slit of proper length at the bottom edge or at the tip of the embedded triangular slot, CP radiation can easily be achieved by using a single probe feed. Results indicate that, at a fixed operating frequency, the proposed designs can have good CP radiation characteristics with a reduced antenna size of about 30% compared to the regular-size CP design using a simple triangular patch.
TL;DR: In this paper, a stacked microstrip patch antenna for dual-band applications is presented, which covers the frequency bands 890-960 MHz and 1.71-1.88 GHz, respectively.
Abstract: Results for a stacked microstrip patch antenna for dual-band applications are presented. The aim is to cover the frequency bands 890–960 MHz and 1.71–1.88 GHz, respectively. Impedance bandwidths (VSWR <2 : 1) of 20.1 and 14.8% were obtained for the respective frequency bands. Simulated as well as measured results for the antenna are presented. © 2001 John Wiley & Sons, Inc. Microwave Opt Technol Lett 31: 289–292, 2001.
04 Jun 2001
TL;DR: In this paper, a microstrip-to-stripline-to microstrip coupler was built and tested to illustrate the idea of suppression of the parallel plate mode in striplines.
Abstract: This paper describes the implementation of a new approach in the suppression of the parallel plate mode in striplines. A microstrip-to-stripline-to microstrip coupler was built and tested to illustrate the idea. Finally a sixteen-element microstrip array fed by this new type of feeding network was built and tested at C-band. The building of this array at C-band was a first step towards the application of this technology at higher frequencies, where the integration of the antenna with the rest of the system is required.
01 Jan 2001
TL;DR: In this paper, the use of microstrip dipole antenna structures for the detec- tion of mid-infrared radiation was demonstrated, for the first time, using a 2.2 crobolometer integrated with a twin rectangular microstrip patch antenna.
Abstract: 2 crobolometer integrated with a twin rectangular microstrip patch antenna. This letter demonstrates, for the first time, the use of microstrip dipole antenna structures for the detec- tion of midinfrared radiation. The difference between a printed dipole 2 and a printed microstrip dipole is that the latter is placed a fraction of a free-space wavelength above a metallic ground plane. The presence of the ground plane leads to a better confinement of the electromagnetic fields under the dipole, and thus to a higher antenna quality factor. Furthermore, for the same dielectric spacer thickness, a half-wavelength microstrip dipole has a narrower bandwidth than a rectangular microstrip patch antenna 6 . Infrared antennas are essentially scaled-down versions of their counterparts found in the microwave portion of the electromagnetic spectrum. However, as the frequency of op- eration increases, so does the energy dissipation within the materials involved in the fabrication of the antennas. The typical thickness of the layers that make up an antenna-cou- Ž. pled infrared IR detector is about 100 nm. The physical parameters of such thin layers depend on the details of the deposition conditions. Therefore, the material data available in the literature can only provide a starting point for the design of infrared antennas. Full-wave electromagnetic techniques such as the method Ž. Ž .
18 Sep 2001
TL;DR: In this article, the power transmission line consists of both an antenna generating a long beam of electromagnetic waves and a receiving antenna (rectenna) located in the Fresnel zone, and two problems are investigated: to what extent this field can be close to a given field and how to make this field quickly diminish far from the rectenna.
Abstract: The power transmission line consists of both an antenna generating a long beam of electromagnetic waves and a receiving antenna (rectenna) located in the Fresnel zone. By choice of antenna field one can make the field on the rectenna plane meet different requirements. Two problems are investigated: to what extent this field can be close to a given field and how to make this field quickly diminish far from the rectenna. The 2D case is considered.
04 Jun 2001
TL;DR: In this paper, the equations of planar microstrip antenna that represent the electromagnetic fields in the x and z direction as function of the electric field in the y direction were obtained applying the TTL method, at the first time.
Abstract: The equations of planar microstrip antenna that represents the electromagnetic fields in the x and z direction as function of the electric field in the y direction are obtained applying the TTL method, at the first time. This method is very suitable at microwave and antenna applications, and gives accurate complex resonant frequency which contributes to obtain higher precision antenna parameters.