نتایج جستجو برای: antenna feed
تعداد نتایج: 109117 فیلتر نتایج به سال:
the methods which are used to analyze microstrip antennas, are divited into three categories: empirical methods, semi-empirical methods and full-wave analysis. empirical and semi-empirical methods are generally based on some fundamental simplifying assumptions about quality of surface current distribution and substrate thickness. thses simplificatioms cause low accuracy in field evaluation. ful...
In this paper a microstrip antenna on a suspended substrate with capacitive feed is presented. capacitive feed is created by a slot within the rectangular patch around the feed point. The proposed antenna exhibits a much higher impedance bandwidth of about 47% (S11 < −10 dB). Effects of key design parameters such as the air gap between the substrate and the ground plane, the gap width between r...
in this article, the linear array (with 20 elements in the horizontal orientation) of microstrip antenna is examined with horizontal polarization. the set includes three microstrip substrates. there is a power network in two lower substrates and microstrip patches in the upper substrate. excitation of patches has been done as coupled through the power network in two lower substrates. using the ...
lenses are often used to converge electromagnetic wave namely they convert incident phase front of feed antenna to a flat phase front. together, the lens and the feed create an electrically large aperture antenna. flat lenses provide the cost and weight benefits of the reflect-arrays, while maintaining the advantages of a lens antenna. these lenses use an array of unit-cells which are excited b...
The Eleven antenna has constant beam width, constant phase center location, and low spillover over a decade bandwidth. Therefore, it can feed a reflector for high aperture efficiency (also called feed efficiency). It is equally important that the feed efficiency and its subefficiencies not be degraded significantly by installing the feed in a cryostat. The MIT Haystack Observatory, with guidanc...
In the design of circular patch antenna, the feed point locations SF=5, SF=6, SF=7 and SF=8 were selected and the simulated results compared and the optimum location adopted and implemented. The best feed point was located at SF=5mm where return loss RL is -37.81dB, followed by SF=6mm with return loss RL of -17.14dB and SF=7mm with return loss RL is -11.38dB. The feed point location at SF=8mm w...
This paper presents the results of a new monopole antenna that exhibits 2.75-10.7 GHz performance. The proposed antenna consists of a radiating patch with notches excited by capacitive coupling feed. Also, the antennas truncated ground-plane incorporates a central notch. This modification significantly improves the antennas impedance bandwidth by 118% over an ultra-wideband frequency range. T...
in this paper, a resonant slotted waveguide array antenna with circular boundary has been designed and simulated for mono-pulse airborne radar applications. the antenna parameters are:11% bandwidth in x-band (8.6-9.6ghz),vswr < 2, 38dbi directivity, sidelobes level of - 20db and 3-db beam-widths of 2.1degree. to design this antenna, it is divided into short sections (sub-arrays) each with a uni...
This paper proposes a patch antenna array as an alternative feed for dish antennas on board satellites to solve the weight problem constituted by conventional feed horns. An 8x1 linear, C-Band, circular patch antenna array configuration with a broadside radiation pattern is designed as feed for a dish antenna with F/D ratio of 0.36 corresponding to aperture illumination of 140. The result of an...
In this paper, a new antenna is presented which has an application in cellular telecommunication systems. The designed antenna works at the frequency range of 1900-2600 MHz which is able to cover 2G, 3G and 4G (LTE) services of the cellular telecommunication. In this paper, the micro-strip structure has been used to design the antenna. The shape of the patches is triangular where a peripheral r...
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