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Printed Antenna Arrays with High Side Lobe Suppression  [PDF]
Aleksandar Ne i ,Ivana Radnovi ,Zoran Mi i
Active and Passive Electronic Components , 2008, DOI: 10.1155/2008/542929
Abstract: The problem of side lobe suppression (SLS) in printed antenna arrays has been investigated in the paper. Influence of several factors that make difficult design and realization of antenna arrays with relatively high SLS has been analyzed. We introduced a new type of printed antenna array with symmetrical pentagonal dipoles and symmetrical tapered feed network with Chebyshev distribution enabling SLS better than 34 dB in E-plane. Agreement between simulated and measured results is very good. The antenna is suitable for integration with other microwave circuits. Presented antenna is low cost and very simple for realization.
Is the far border of the Local Void expanding?  [PDF]
I. Iwata,P. Chamaraux
Physics , 2011, DOI: 10.1051/0004-6361/201116687
Abstract: According to models of evolution in the hierarchical structure formation scenarios, voids of galaxies are expected to expand. The Local Void (LV) is the closest large void, and it provides a unique opportunity to test observationally such an expansion. It has been found that the Local Group, which is on the border of the LV, is running away from the void center at ~260 km/s. In this study we investigate the motion of the galaxies at the far-side border of the LV to examine the presence of a possible expansion. We selected late-type, edge-on spiral galaxies with radial velocities between 3000 km/s and 5000 km/s, and carried out HI 21 cm line and H-band imaging observations. The near-infrared Tully-Fisher relation was calibrated with a large sample of galaxies and carefully corrected for Malmquist bias. It was used to compute the distances and the peculiar velocities of the LV sample galaxies. Among the 36 sample LV galaxies with good quality HI line width measurements, only 15 galaxies were selected for measuring their distances and peculiar velocities, in order to avoid the effect of Malmquist bias. The average peculiar velocity of these 15 galaxies is found to be -419+208-251 km/s, which is not significantly different from zero. Due to the intrinsically large scatter of Tully-Fisher relation, we cannot conclude whether there is a systematic motion against the center of the LV for the galaxies at the far-side boundary of the void. However, our result is consistent with the hypothesis that those galaxies at the far-side boundary have an average velocity of ~260 km/s equivalent to what is found at the position of the Local Group.
Design of Printed Dipole Array for Omnidirectional Radiation Pattern  [PDF]
Jean-Marie Floc’h
Wireless Engineering and Technology (WET) , 2019, DOI: 10.4236/wet.2019.102002
Abstract: In this paper, we describe 2 kinds of printed dipole arrays and compare the performances of these arrays in term of reflexion coefficient, radiation pattern and dimensions. It is interesting to design array in order to obtain better performances in term of omnidirectional radiation pattern in comparison with single element. We choose this elementary source in order to obtain compact array with good performances. These antenna arrays are designed to have omnidirectional radiation pattern with horizontal polarization. We present an application dedicated to compact base station in the last section.
On the Design of Planar Printed Dipole Array Antennas  [PDF]
Jean-Marie Floc’h, Ahmad El Sayed Ahmad, Anne Claude Tarot, Renaud Loison, Sophia Thizon, JeanYves Daden
Wireless Engineering and Technology (WET) , 2012, DOI: 10.4236/wet.2012.34029
Abstract: In this paper, we propose a new design procedure for printed dipole array antennas. Applications of these arrays are devoted to wireless communication systems, mainly base stations and beam steerable antennas. All the designs have been developed at the frequency of 3 GHz. This structure is chosen in order to enhance the gain and minimize the backside radiations of an antenna array with a very simple feeding.
Microstrip Phased Array Antennas Printed on Inclined Planes
D. Augustin,R. Staraj,E. Cambiaggio,A. Papiernik
Radioengineering , 1996,
Abstract: This paper presents an analysis of the electromagnetic field radiated by micro-strip patch antennas printed on inclined surfaces. The theoretical approach allows to apply spatial rotations to each source. The computer simulation developed permits us to experiment different antenna structures and two original realisations are proposed: a 2-element array printed on two inclined planes and a 4-element array laid out on a pyramidal surface. In addition, it enables the choice of the phase applied to each radiator to produce a beam deflection function. A good accuracy is obtained between theoretical and experimental results. The aim of this study is to optimise the parameters of such antennas to achieve the desired radiation patterns, from printed phased arrays on conformal surfaces. We also present the theoretical behaviour of a octagonal pyramid.
Simplified Printed Log-Periodic Dipole Array Antenna Fed by CBCPW  [PDF]
Guohua Zhai,Yong Cheng,Qiuyan Yin,Shouzheng Zhu,Jianjun Gao
International Journal of Antennas and Propagation , 2013, DOI: 10.1155/2013/548610
Abstract: A novel simple approach for designing single-layer printed log-periodic dipole array (PLPDA) antenna fed by conductor-backed coplanar waveguide (CBCPW) is presented. The PLPDA antenna has the merits of wide bandwidth, low profile, and stable radiation pattern, which should be fed by the balanced line. The balanced line, created by the geometric features of the CBCPW, provides a balun with a considerably wide bandwidth with low profile, broad bandwidth, low insertion loss, and so forth. The prototype of the proposed CBCPW-fed printed log-periodic array at Ka band is designed and fabricated; the measured data are in good agreement with the simulated results. 1. Introduction As an end-fire type antenna, the log-periodic dipole array (LPDA) antenna has the merits of fixed peak radiation and stable radiation pattern within the operating frequency, so it is one of the candidates for the modern wireless communications system. Numerous studies have been documented on the design method and the performance of the conventional LPDA antenna since the 1960s [1–7]. In order to achieve low profile, printed log-periodic dipole arrays (PLPDA) antenna was proposed based on the printed integrated board (PCB) technology [8–14]. Practically, the performance of the PLPDA antenna is determined by the feeding network. At an early stage, the PLPDA antenna was designed on a piece of the double-layer printed circuit board [8–11], but it increases the fabrication cost and limits the productivity. Then, the fabrication cost is reduced by using single-layer printed circuit, so the single-layer PLPDA antennas with two coaxial cables as the feeding network were proposed [12, 13]. However, soldering coaxial cables bring significant fabrication error and misalignment, especially at millimeter-wave frequencies. A single-layer slot PLPDA antenna fed by coplanar waveguide (CPW) was proposed [14], the CPW transmission line has been widely used in the monolithic millimeter-wave integrated circuits (MMIC), but this transmission line suffers from high insertion loss in the transition, radiation loss, serious crosstalk, and lower power handling capability because of its open structure. Recently, the substrate integrated circuits (SIC) concept, in particular substrate integrated waveguide (SIW) technique, has been demonstrated as a promising scheme for low-cost, small size, relatively high power, low radiation loss, and high-density integrated microwave and millimeter-wave components and systems, which has been widely used in the low profile antenna design [15–18]. And the substrate integrated
Experimental Validation of Linear Aperiodic Array for Grating Lobe Suppression
S. Suarez;German Leon Fernandez;Manuel Arrebola;Luis Fernando Herran Ontanon;Fernando Las Heras Andres
PIER C , 2012, DOI: 10.2528/PIERC11110706
Abstract: In this paper, a deterministic strategy to generate the aperiodicity, based on three geometric taper distributions is studied and validated. The method is applied to study arrays with average inter-elements spacing larger than a wavelength, exhibiting a reduction of the grating lobe level and requiring lower aperture size against a periodic structure with same directivity. Finally, a microstrip patch aperiodic array has been designed, manufactured and measured for an experimental validation of the concept, obtaining good agreement between simulated and measured radiation patterns. This manufactured antenna demonstrates experimentally the reduction of the grating lobes with a similar level to the side lobe.
Efficient Analysis for the Design Refinement of Large Multilayered Printed Reflectarrays
F. De Vita,P. De Vita,A. Freni
Radioengineering , 2011,
Abstract: In this paper, we present an efficient numerical technique for the analysis of a reflectarray and its design refinement by the characterization of the “actual” influence of each radiating element when embedded in the antenna structure. The method makes use of the MLayAIM, a fast full-wave formulation suitable for the analysis of electrically large multilayered printed arrays which have one or more planar metallizations and vertical conductors. The low numerical complexity of the analysis method allows the development of a recursive procedure that, starting from the equivalent currents relevant to each cell of the reflectarray when this is immersed in the actual antenna layout, calculates the real phase-shift introduced by each radiating element and corrects its dimensions to better fit the antenna requirements.
Design of Printed Yagi Antenna with Additional Driven Element for WLAN Applications
Jafar Ramadhan Mohammed
PIER C , 2013, DOI: 10.2528/PIERC12121201
Abstract: A new configuration of Yagi antenna is proposed, which can improve the forward/backward ratio (f/b) significantly while maintaining a high gain. This configuration involves the addition of one radiating element (dipole) to the original Yagi array which produces a controllable pattern used for cancellation of back lobe. This additional element may arrange on parallel (side-by-side) or collinear to a radiating dipole of the original Yagi antenna. It is shown here that the technique is most effective for collinear configuration (exhibits smaller mutual effects) and that there then exists an optimum length and position for the added element. The amplitude of the excitation of the additional element determines the angular location of the back lobe reduction. To demonstrate the major benefits, comparisons are made among the proposed and conventional Yagi configurations. Numerical and measured results of our design show more than 20 dB front to back ratio at 2.4 GHz. To the author's knowledge, this is the first printed Yagi antenna presented that has a high gain and a high f/b ratio designed using simple technique. Moreover, the proposed array represents a simple and valuable alternative to the stack Yagi antennas as the obtainable radiation characteristics are satisfactory in terms of both forward and backward gain.
A Comparative Performance Analysis of Two Printed Circular Arrays for Power-Based Vehicle Localization Applications  [PDF]
Mohammad S. Sharawi,Farooq Sultan,Daniel N. Aloi
International Journal of Antennas and Propagation , 2012, DOI: 10.1155/2012/567918
Abstract: A comparative study of the performance characteristics of a printed 8-element V-shaped circular antenna array and an 8-element Yagi circular array operating at 2.45?GHz for vehicular direction finding applications is presented. Two operating modes are investigated; switched and phased modes. The arrays were fabricated on FR-4 substrates with 0.8?mm thickness. Measured and simulated results were compared. Radiation gain patterns were measured on a 1?m diameter ground plane that resembles the rooftop of a vehicle. The HPBW of the Yagi was found to be about 3° narrower than its V-shaped counterpart when measured above a reflecting ground plane and operated in switched mode. The printed V-shaped antenna array offers 2.5?dB extra gain compared to the printed Yagi array. 1. Introduction Increased usage of tracking devices in cars raised the need for the development of highly accurate position determination systems. One of the basic requirements for radio frequency (RF) vehicular localization is the accurate estimation of the direction of arrival (DOA) of the incoming RF signal [1]. Recent advances in smart antenna technologies—antennas with digital signal processing (DSP) equipment—enabled the enhancement of antenna coverage and efficient utilization of the transmitted power. In a bid to accommodate the maximum possible number of users, cellular service providers are utilizing smart antenna systems to shape the radiation patterns to focus their transmit power in a given region. Traditionally, highly accurate DOA systems require the use of multiple receivers with separate antennas integrated with DSP algorithms like the multiple signal classification (MUSIC) and rotational invariance techniques (ESPRIT) [2, 3]. The use of multiple receivers dictated the size of the overall system to be large making it difficult to deploy for several applications. For increased practicality, microstrip antenna arrays are used nowadays to save space and to decrease the overall profile of the system. As the number of cars globally increases beyond the 1 billion mark [4], parking problems in densely populated cities have started to increase. Indoor, multistory parking lots are being considered as one of the most efficient ways of providing parking space for the available cars without interrupting the traffic flow. An emerging application of DF systems is for car localization in huge parking lots. The majority of modern cars are equipped with remote entry systems which can help in locating the car when the transmitter (key) is triggered within a specific distance from the receiver
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