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ENLARGING SAR PATCH-MAPPING AREA BY ANTENNA BEAM SCAN 被引量:1
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作者 朱岱寅 朱兆达 叶少华 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI 2003年第2期201-204,共4页
The approach for enlargement of SAR patch mapping area by antenna beam scan is investigated, which serves for moderate fine-resolution mapping of medium-sized terrain patches. The scanning angular velocity and the sca... The approach for enlargement of SAR patch mapping area by antenna beam scan is investigated, which serves for moderate fine-resolution mapping of medium-sized terrain patches. The scanning angular velocity and the scanning angular scope are determined respectively. The angular velocity of the scanning antenna is controlled to scan over just one azimuth 3 dB beam width in the time interval during which the radar platform moves over one synthetic aperture length determined from the desired cross-range resolution, radar wavelength, nominal slant range, and squint angle. The scanning angular scope is mainly determined by the azimuth width of the terrain patch, nominal slant range, squint angle, platform velocity, and azimuth beam width. Finally, the related experimental results of an airborne SAR are presented. The linear range-Doppler algorithm is employed in image formation after motion compensation is conducted to remove the effect of transnational motion of the radar platform relative to the map center. 展开更多
关键词 SAR antenna beam scan patch-mapping
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Practical realization of dual S arm antenna for beam steering applications
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作者 MEHTA Amit 《Journal of Zhejiang University-Science A(Applied Physics & Engineering)》 SCIE EI CAS CSCD 2007年第12期1901-1904,共4页
A dual S shaped micro strip antenna with a realistic feed is proposed for generation of tilted beam radiation pattern pertaining for beam steering applications. To achieve this, four feeding points are located at a di... A dual S shaped micro strip antenna with a realistic feed is proposed for generation of tilted beam radiation pattern pertaining for beam steering applications. To achieve this, four feeding points are located at a distance of 5.6 mm from the antenna centre. These feeding points when excited one by one generate four tilted beams in four different space quadrants, thus yielding a beam steerable antenna, Importantly, since the proposed antenna is symmetrical in the structure, all the four tilted beams have the same radiation pattern characteristics. A further enhancement of the antenna bandwidth is also achieved using 100-μn capacitive coupling between the feed and the antenna strip. 展开更多
关键词 Beam steerable antenna S antenna. Switched beams
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A 2.4 GHz Switched Beam Antenna for Indoor Applications Using Angle of Arrival Estimation
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作者 Reham Elsamnty Ahmed Mohamed Attiya +1 位作者 Esmat Abdel Fattah Abdallah Abdel Hadi Ammar 《Open Journal of Antennas and Propagation》 2016年第3期109-118,共11页
This study introduces a new design of planar antenna array for ISM band applications at 2.4 GHz. This prototype is switched beam antenna, namely planar antenna with four meandered slotted triangular elements (PAFMSTE)... This study introduces a new design of planar antenna array for ISM band applications at 2.4 GHz. This prototype is switched beam antenna, namely planar antenna with four meandered slotted triangular elements (PAFMSTE), which is proposed for wireless indoor applications. The Base Station (BS) equipped with this planar antenna is preferred to be at the center position on the room ceiling to cover all sectors of the room. It is designed to use four directional triangular elements arranged to form a square planar antenna array. The PAFMSTE is used to obtain optimal directivity in four directions in azimuth plane with 3 dB beamwidth of 90&deg;at a specific orientation of 30&deg;in elevation plane. Switched parasitic technique is used to enable PAFMSTE to steer a directional beam through four locations by using four PIN diodes switches. The High Frequency Structure Simulator (HFSS) is used as an efficient simulation tool to optimize the performance of the PAFMSTE antenna. The fabrication and measurements of the PAFMSTE antenna are introduced. The proposed antenna enable radio positioning via Angle of Arrival (AOA) information collected from nearby devices. Then, the Cramér-Rao Bound (CRB) is presented for AOA estimation using identically and equally spaced antenna elements. The CRB depends on the directivity, where the maximum values of CRB are 1.35 × 10<sup>-3</sup> and 8 × 10<sup>-3</sup> at HPBW of 60° and 90°, respectively. 展开更多
关键词 Indoor Communications Switched Beam antenna Directional Microstrip antenna Slotted Patch antenna Radio-Positioning AOA Estimation CRB
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GA BASED SYNTHESIS OF SATELLITE-BORNE MULTI-BEAM PLANAR ARRAY WITH ARBITRARY GEOMETRY 被引量:2
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作者 Jin Jun Wang Huali Zhu Wenming Liu Yunzhi 《Journal of Electronics(China)》 2006年第4期637-640,共4页
A planar array antenna with arbitrary geometry synthesis technique based on genetic algorithm is discussed. This approach avoids coding/decoding and directly works with complex numbers to simplify computing program an... A planar array antenna with arbitrary geometry synthesis technique based on genetic algorithm is discussed. This approach avoids coding/decoding and directly works with complex numbers to simplify computing program and to speed up computation. This approach uses two crossover operators that can over-come premature convergence and the dependence of convergence on initial population. Simulation results show that this method is capable of synthesizing complex pattern shapes of planar arrays with arbitrary ge-ometry and can realize good sidelobe suppression at the same time. 展开更多
关键词 Genetic algorithm antenna array Pattern synthesis Shaped beam antennas
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Realizing complex beams via amplitude-phase digital coding metasurfaces and semidefinite relaxation optimization
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作者 Junwei WU Qiong HUA +4 位作者 Hui XU Hanqing YANG Zhengxing WANG Qiang CHENG Tie Jun CUI 《Frontiers of Information Technology & Electronic Engineering》 SCIE EI CSCD 2023年第12期1708-1716,共9页
Complex beams play important roles in wireless communications,radar,and satellites,and have attracted great interest in recent years.In light of this background,we present a fast and efficient approach to realize comp... Complex beams play important roles in wireless communications,radar,and satellites,and have attracted great interest in recent years.In light of this background,we present a fast and efficient approach to realize complex beams by using semidefinite relaxation(SDR)optimization and amplitude-phase digital coding metasurfaces.As the application examples of this approach,complex beam patterns with cosecant,flat-top,and double shapes are designed and verified using full-wave simulations and experimental measurements.The results show excellent main lobes and low-level side lobes and demonstrate the effectiveness of the approach.Compared with previous works,this approach can solve the complex beam-forming problem more rapidly and effectively.Therefore,the approach will be of great significance in the design of beam-forming systems in wireless applications. 展开更多
关键词 antenna beams Amplitude-phase coding metasurface Far-field synthesis Semidefinite relaxation
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