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Microstrip Antennas (microstrip + antennas)
Selected AbstractsMicrostrip antennas for cellular and wireless communication systemsMICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 5 2002obodzian Abstract The Letter describes problems related to use of microstrip antennas in cellular and wireless telecommunications systems. Because of the unique properties, microstrip technology is nowadays often used to manufacture small internal antennas for portable terminals as well as antenna arrays for base stations. It also seems to be a very promising technology for multisystem antennas, for which there is an ever-growing demand. The Letter also presents a short overview of currently available solutions and ones under development by the authors, along with some key problems related to their design. © 2002 Wiley Periodicals, Inc. Microwave Opt Technol Lett 34: 380,384, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.10468 [source] Probe compensated single feed circularly polarized fractal-shaped microstrip antennasINTERNATIONAL JOURNAL OF RF AND MICROWAVE COMPUTER-AIDED ENGINEERING, Issue 6 2009P. Nageswara Rao Abstract A single feed circularly polarized fractal boundary microstrip antenna with improved axial ratio bandwidth is presented. The low-axial ratio bandwidth of single feed circularly polarized microstrip antenna is due to its probe reactance. In this article, the inherent disadvantage of this low-AR bandwidth is overcome by compensating the probe reactance by incorporating capacitance in the form of small patch between the radiating patch and the probe. The perturbation of the patch is done using fractal curve as boundary. The proposed antenna exhibits impedance and axial ratio bandwidths of 9 and 2.2% respectively at 2.4 GHz. © 2009 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2009. [source] Probe-fed microstrip antennas loaded with very high-permittivity ceramicsINTERNATIONAL JOURNAL OF RF AND MICROWAVE COMPUTER-AIDED ENGINEERING, Issue 5 2006Y. Hwang Abstract This article reports the feasibility study of miniaturizing probe-fed microstrip patch antennas by dielectric loading. The loading materials are barium tetratitanate ceramics of very high dielectric constant (,r = 38, 80). It is shown that, simply through loading, the antenna sizes are greatly reduced; however, the antenna performances are deteriorated. For instance, the antenna gain becomes lower. Then enhancement of the antenna performances follows. A substrate,superstrate structure is used to recover the gain. Both the experiments and the finite-difference time-domain (FDTD) simulations demonstrate that the gain and impedance bandwidth can be retrieved such that they are comparable to those of conventional microstrip antennas loaded with low permittivity materials (,r < 3). © 2006 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2006. [source] Edge feeding of circular patch microstrip antennasINTERNATIONAL JOURNAL OF RF AND MICROWAVE COMPUTER-AIDED ENGINEERING, Issue 2 2001B. S. Rao Abstract Edge feeding of a circular patch antenna by a microstrip line has been achieved by utilizing the circumferential variation of the field which is fixed by loading the patch. However, loading splits the degenerate modes and gives rise to cross-polarization. Three different techniques are presented to analyze the loaded circular patch antenna. Comparison with the measured results for input impedance and radiation patterns shows good agreement. The concept used here is very general and can be applied to the edge feeding of any ring antenna. © 2001 John Wiley & Sons, Inc. Int J RF and Microwave CAE 11: 74,85, 2001. [source] Slits-loaded microstrip antennas for circular polarizationMICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 9 2010N. Nasimuddin Abstract Novel diagonally slits-loaded compact microstrip antennas are proposed for circular polarization (CP). A group of four slits is loaded on the square patch radiator for compact antenna size with CP radiation. The slit with unequal sizes loaded on square patch in diagonal directions is used to achieve CP radiation. The combined V -shaped and square slits, diagonally loaded, microstrip antenna is compact when compared with V -shaped slits loaded microstrip antenna. The measured 10-dB return loss and 3-dB axial-ratio bandwidths are 3.55% and 0.82%, respectively, for a combined V -shaped and square slits loaded microstrip patch antenna. The overall size of the antenna is 0.256,0×0.256,0×0.0136,0 at 2.55 GHz. The proposed slits-loaded patch radiator is useful for compact circularly polarized microstrip antenna and array designs. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 2043,2049, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.25417 [source] Resonance frequency of hexagonal and half hexagonal microstrip antennasMICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 2 2009K. P. Ray Abstract Closed form expressions for the accurate calculation of the resonance frequency of a hexagonal and half hexagonal microstrip antennas, based on their equivalence with rectangular microstrip antenna, have been presented. These proposed empirical formulae have been validated using simulations and experiments. Design curves, for the input impedance variation along the feed axis, have been presented for hexagonal and half hexagonal patches for two feed positions. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 448,452, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24087 [source] Gain enhancement in embedded microstrip antennasMICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 2 2008M. Fallah-Rad Abstract A microstrip antenna embedded inside a dielectric medium representing the building material is investigated for its gain. It is shown that coupling the embedded antenna to a parasitic patch, placed outside the embedding material, can increase the antenna gain significantly. In addition, by properly selecting the antenna depth inside the embedded material its radiation characteristics can be made less sensitive to the material parameters of the surrounding. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 269,271, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23070 [source] Broadband gap-coupled half hexagonal microstrip antennasMICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 2 2008K. P. Ray Abstract Three configurations of compact gap-coupled half hexagonal microstrip antennas have been presented for broad bandwidth. Parametric studies for the effect of coupling gap and feed point location on the performance of these antennas have been investigated and the results have been validated experimentally. Increase in bandwidth is more than twice for the two configurations and about four times for the third case when compared with that of the corresponding hexagonal microstrip antenna. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 271,275, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23069 [source] A discussion on the performance of impedance matched antenna system and considerations for a better performanceMICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 2 2008Adnan Kaya Abstract Impedance matching networks are used extensively in radio communications. In this study, ,-matching circuit has been used as a matching network. The return loss level of several impedance matched microstrip antennas are compared as a function of matching techniques. The ,-matching device is used to construct the antenna tuning units, which is only used to match the front module and the antenna. This circuit impedance region has been investigated analytically under the variable load condition. When the mismatch is occurred, the result is an increase in the energy consumption or transmission quality deterioration. In addition, the input module in antenna system could be damaged if reflection of the signal levels is excessively high. This is interesting application because antennas cannot be considered alone as component with changing electromagnetic properties. The rectangular microstrip antenna was designed at 2.5 GHz frequency by using microstrip feed line. Better return loss level which is ,16.86 dB has been obtained for this antenna using ,-matching circuit. It is shown that theoretical, simulation, and laboratory results are good agreement. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 410,415, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23101 [source] Calculation of optimized parameters of rectangular microstrip patch antenna using particle swarm optimizationMICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 12 2007A. Egemen Yilmaz Abstract In this letter, the particle swarm optimization has been applied to calculate the optimized length and width of rectangular microstrip antennas. The inputs to the problem are the dielectric constant and thickness of the substrate; together with the desired resonant frequency; the outputs are the optimized length and width; where the antennas are considered to be electrically thin. The results are in good agreement with the results (experimental and calculated by other heuristics) in the literature. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 2905,2907, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22918 [source] Dual-band patch antenna on magnetic substrate for WLAN communicationMICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 6 2007Wang Encheng Abstract This article introduces a novel dual-band patch antenna printed on organic magnetic substrate for WLAN communication, operating at 2.45 and 5 GHz. The dual-band operation is obtained through embedding a pair of L-shaped slots. The antenna has smaller size for the use of magnetic material, compared with rectangular microstrip antennas on normal dielectric substrate. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 1445,1447, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22405 [source] Formulation of resonant frequency for compact rectangular microstrip antennasMICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 2 2007Amit A. Deshmukh Abstract The approximate equations to calculate the resonant length of various compact rectangular microstrip antennas like, C-shaped, H-shaped, and rectangular ring microstrip antenna, are proposed. The error in the calculated resonance frequency is <5%. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 498,501, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22161 [source] An efficient neural network model for the input resonant resistance of coaxial fed rectangular microstrip antennas with thin and thick substratesMICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 11 2006Serkan Abstract In this paper, an efficient neural network model is suggested to determine the input resonant resistance of coaxial fed rectangular microstrip antennas (MSAs) with thin and thick substrates. The NN results are in good agreement with experimental results reported in literature. This method can easily be modified to address problems involving more general types of MSAs. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 2197,2199, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21908 [source] Adaptive neuro-fuzzy inference system for computing patch radius of circular microstrip antennasMICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 8 2006Kerim Guney Abstract A new method based on the adaptive neuro-fuzzy inference system (ANFIS) is presented to calculate accurately the patch radius of circular microstrip antennas (MSAs). ANFIS combines the benefits of artificial neural networks (ANNs) and fuzzy inference systems (FISs) in a single model. A hybrid learning algorithm based on the least-squares method (LSM) and the backpropagation algorithm is used to identify the parameters of ANFIS. The results of ANFIS are in very good agreement with the experimental results reported elsewhere. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 1606,1610, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21695 [source] Circularly polarized proximity-coupled microstrip antennasMICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 5 2005Yi-Lung Lee Abstract A novel design for the production of circularly polarized radiation (CP) in proximity-fed microstrip antennas is presented. To achieve this circular-polarization design, the two orthogonal modes of the microstrip antenna are excited in series through the proximity coupling of an L-shaped open microstrip line. The experimental results show that the 3-dB axial-ratio CP bandwidth of the proposed design is increased by more than 30%, as compared to a conventional CP microstrip antenna of the same size. The details of the simulated and experimental results for the proposed design are presented and discussed. © 2005 Wiley Periodicals, Inc. Microwave Opt Technol Lett 46: 429,430, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21006 [source] Microstrip antennas for cellular and wireless communication systemsMICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 5 2002obodzian Abstract The Letter describes problems related to use of microstrip antennas in cellular and wireless telecommunications systems. Because of the unique properties, microstrip technology is nowadays often used to manufacture small internal antennas for portable terminals as well as antenna arrays for base stations. It also seems to be a very promising technology for multisystem antennas, for which there is an ever-growing demand. The Letter also presents a short overview of currently available solutions and ones under development by the authors, along with some key problems related to their design. © 2002 Wiley Periodicals, Inc. Microwave Opt Technol Lett 34: 380,384, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.10468 [source] Parametric and temperature-sensitivity study of resonance frequency of microstrip antennas using spectral-domain methodMICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 4 2001Ashutosh Kedar Abstract In the present paper, a study is carried out to visualize the effects of various design parameters, including temperature, on the resonant frequency of a microstrip patch antenna. The analysis is carried out using the spectral-domain method with efficient evaluation of infinite 2-D reaction integrals improving the rate of convergence. Some of the numerical results are compared with the experimental data. © 2001 John Wiley & Sons, Inc. Microwave Opt Technol Lett 30: 276,280, 2001. [source] | ||||||||||