摘要 :
A compact, low profile four-element helical array antenna is proposed and investigated in this article. This antenna comprises 4 turn helices. The single helical antenna and four-element array antenna are designed and simulated us...
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A compact, low profile four-element helical array antenna is proposed and investigated in this article. This antenna comprises 4 turn helices. The single helical antenna and four-element array antenna are designed and simulated using ANSYS HFSS. A binary tree corporate feed network is used to distribute power equally among the antennas. The resonating frequency of the proposed antenna is 12GHz and can be used for high bandwidth and high gain applications. The results stipulate its advantages of high efficiency, high directivity, and a favorable axial ratio. The number of elements in the array was increased from 4 to 16 employing the sub-array technique and a comparison was done between this antenna and dish antenna which is generally used for satellite communication purposes.
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摘要 :
A compact, low profile four-element helical array antenna is proposed and investigated in this article. This antenna comprises 4 turn helices. The single helical antenna and four-element array antenna are designed and simulated us...
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A compact, low profile four-element helical array antenna is proposed and investigated in this article. This antenna comprises 4 turn helices. The single helical antenna and four-element array antenna are designed and simulated using ANSYS HFSS. A binary tree corporate feed network is used to distribute power equally among the antennas. The resonating frequency of the proposed antenna is 12GHz and can be used for high bandwidth and high gain applications. The results stipulate its advantages of high efficiency, high directivity, and a favorable axial ratio. The number of elements in the array was increased from 4 to 16 employing the sub-array technique and a comparison was done between this antenna and dish antenna which is generally used for satellite communication purposes.
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摘要 :
Reconfigurable antenna implementation can be separated into three main processes: Antenna design, simulation, and optimization. The objective of this paper is to provide insight into the selections that must be made to implement a...
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Reconfigurable antenna implementation can be separated into three main processes: Antenna design, simulation, and optimization. The objective of this paper is to provide insight into the selections that must be made to implement a reconfigurable antenna, serving as a guideline for future reconfigurable antenna designers as to what needs to be done before a model is constructed, such as choosing a suitable antenna structure and reconfiguration technology, a proper simulation environment, and an adequate optimization algorithm that will allow smooth transitions between reconfigurable states. These selections are directly dependent on the given project requirements. Several options are presented for each case, and particular selections are made based on desired characteristics.
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The effect of human body on wearable 100 MHz antennas is studied by measurements. At that frequency, the body is very thin compared to the wavelength, but about half a wavelength tall. Antenna performance is most affected by the p...
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The effect of human body on wearable 100 MHz antennas is studied by measurements. At that frequency, the body is very thin compared to the wavelength, but about half a wavelength tall. Antenna performance is most affected by the posture of the antenna wearer, second matter being antenna position on body. Physical traits of the wearer have only a slight effect on the antenna performance. A -13 dBi gain was achieved by the constructed dipole-like antennas, and letting one's arms hang down reduces this by 5 to 15 dB. Most of the power delivered to the antennas is absorbed by the human body, but some is radiated not only by the antenna but also by the body. Wearable antennas need to be shortened by 15 to 25% from the free-space length to achieve the desired resonance frequency.
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This paper proposes the design of a reflectarray antenna composed of a single-layered periodic arrangement of microstrip elements constituting the reflectarray plane illuminated by a horn antenna operating at Ka-band. The reflecta...
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This paper proposes the design of a reflectarray antenna composed of a single-layered periodic arrangement of microstrip elements constituting the reflectarray plane illuminated by a horn antenna operating at Ka-band. The reflectarray antenna is intended for operating at 19 GHz. The proposed unit cell of the reflectarray is a patch element which forms the shape of ‘E’. The optimization of the dimensions of the element is done to get a linear phase curve. The reflectarray plane consists of 81 elements. The designed horn antenna is placed at offset feed position to dodge the feed blockage. Proper positioning of the horn antenna for correct incident angle along with the selection of reflectarray element parameters gives the desired phase distribution on the reflectarray aperture surface. This results in the increase of the gain of horn antenna by 5.4 dB. The 3-dB beamwidth of the horn antenna has decreased from 48.6° to 12.1° in the E-plane and 49.3° to 13.2° in the H-plane, thus exhibiting more directional beam pattern due to the introduction of the reflectarray structure. Furthermore, the cross-polar radiation is significantly lower than the co-polar radiation for the proposed reflectarray antenna.
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摘要 :
This paper proposes the design of a reflectarray antenna composed of a single-layered periodic arrangement of microstrip elements constituting the reflectarray plane illuminated by a horn antenna operating at Ka-band. The reflecta...
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This paper proposes the design of a reflectarray antenna composed of a single-layered periodic arrangement of microstrip elements constituting the reflectarray plane illuminated by a horn antenna operating at Ka-band. The reflectarray antenna is intended for operating at 19 GHz. The proposed unit cell of the reflectarray is a patch element which forms the shape of ‘E’. The optimization of the dimensions of the element is done to get a linear phase curve. The reflectarray plane consists of 81 elements. The designed horn antenna is placed at offset feed position to dodge the feed blockage. Proper positioning of the horn antenna for correct incident angle along with the selection of reflectarray element parameters gives the desired phase distribution on the reflectarray aperture surface. This results in the increase of the gain of horn antenna by 5.4 dB. The 3-dB beamwidth of the horn antenna has decreased from 48.6° to 12.1° in the E-plane and 49.3° to 13.2° in the H-plane, thus exhibiting more directional beam pattern due to the introduction of the reflectarray structure. Furthermore, the cross-polar radiation is significantly lower than the co-polar radiation for the proposed reflectarray antenna.
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This paper presents a new microwave/millimeter-wave transponder using an active microstrip antenna array. The array elements are arranged by using the Van Atta retrodirectivity design so that the fields radiated from all the trans...
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This paper presents a new microwave/millimeter-wave transponder using an active microstrip antenna array. The array elements are arranged by using the Van Atta retrodirectivity design so that the fields radiated from all the transmitting antennas combine spatially in the wave-incidence direction, which cancel with each other in other directions. The measured returning-field pattern of the transponder is illustrated, which shows good agreement with the calculated pattern.
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An active K/K/sub a/-band antenna array is under development for NASA's ACTS Mobile Terminal (AMT). The AMT active antenna array is a multilayered assembly in which a receive array of radiating slots and a transmit array of micros...
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An active K/K/sub a/-band antenna array is under development for NASA's ACTS Mobile Terminal (AMT). The AMT active antenna array is a multilayered assembly in which a receive array of radiating slots and a transmit array of microstrip dipoles are interleaved such that they share the same aperture to provide a compact, dual-band antenna. The subarrays of the antenna are linear series-fed-type arrays consisting of nearly identical dipole, or slot, elements transversely electromagnetically coupled to a microstrip transmission line. The design and test results for both a dipole and a slot series-fed-type linear array, assuming the impedance characteristics of the radiating elements are known, are described.
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Reflector antennas are broadly utilized antenna in the communication world for various applications like microwave communications, radio space science, radar and satellite applications. This paper dedicated for presently ongoing a...
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Reflector antennas are broadly utilized antenna in the communication world for various applications like microwave communications, radio space science, radar and satellite applications. This paper dedicated for presently ongoing advancement in reflector antenna for microwave applications. The primary goal of this paper is to explore on recent reflector antenna plans to defeat the challenges brought by the developing communication frameworks. It illustrates about the techniques used in recent years to improve the parameters of antennas such as gain, return loss. The bandwidth improvement is very necessary for advanced applications, some of techniques and data are also presented.
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摘要 :
Reflector antennas are broadly utilized antenna in the communication world for various applications like microwave communications, radio space science, radar and satellite applications. This paper dedicated for presently ongoing a...
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Reflector antennas are broadly utilized antenna in the communication world for various applications like microwave communications, radio space science, radar and satellite applications. This paper dedicated for presently ongoing advancement in reflector antenna for microwave applications. The primary goal of this paper is to explore on recent reflector antenna plans to defeat the challenges brought by the developing communication frameworks. It illustrates about the techniques used in recent years to improve the parameters of antennas such as gain, return loss. The bandwidth improvement is very necessary for advanced applications, some of techniques and data are also presented.
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