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Phased array

About: Phased array is a research topic. Over the lifetime, 19428 publications have been published within this topic receiving 229231 citations. The topic is also known as: Phased Array Radar, PAR.


Papers
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Journal ArticleDOI
TL;DR: The signal‐to‐noise ratios (S/Ns) of two different pelvic magnetic resonance imaging phased arrays were compared with that of the body coil to demonstrate the enhanced imaging capability of the phased arrays.
Abstract: The signal-to-noise ratios (S/Ns) of two different pelvic magnetic resonance (MR) imaging phased arrays were compared with that of the body coil. Each array consisted of two coils placed anteriorly and two posteriorly, oriented transversely in one array and longitudinally in the other. S/N measurements were obtained in an adjustable water-filled phantom that stimulated the shape and radio-frequency loading effects of various-size patients. Depending on the simulated anterior-posterior thickness of the patient, the S/N produced by the longitudinal array ranged from 2.3 to 3.1 times higher than that of the body coil. The S/N of the transverse array was 3.1 to 3.4 times higher. The increased coil sensitivity permits imaging with shorter acquisition times, smaller fields of view, finer resolution, and/or thinner sections. Two examples in patients demonstrate the enhanced imaging capability of the phased arrays.

57 citations

Journal ArticleDOI
TL;DR: In this paper, a technique for the synthesis of shaped beam radiation patterns is proposed based on superposition principle and Taylor method, which may control the sidelobe level of the shaped beam.
Abstract: A technique for the synthesis of shaped beam radiation patterns is proposed. The new synthesis method is based on superposition principle and Taylor method. The method may control the sidelobe level of the shaped beam. The approach includes four steps: 1) get the distribution of pencil beam array with low sidelobe by Taylor method; 2) let the beams scan as a phased array to the specific angles according to the requirement of the shaped beam, The sum pattern is close to the shaping beam; 3) determine the value of angles and weights; and 4) count the distribution of the shaped beam array according to the new array factor function. Numerical results are provided to assess the capabilities of the proposed design method. The method develops an effective approach for the synthesis of shaped beams via uniform linear arrays. Both the ripple and sidelobe level of shaped beam may be controlled by the new synthesis method.

57 citations

Journal ArticleDOI
TL;DR: This paper presents a 76-84 GHz low-power 4- element phased array receiver built using a 0.13 μm BiCMOS process and presents state-of-the-art on-chip performance at W-band frequencies.
Abstract: This paper presents a 76-84 GHz low-power 4- element phased array receiver built using a 0.13 μm BiCMOS process. The power consumption is reduced by using a single-ended design and alternating the amplifiers and phase shifter cells to result in a low noise figure at a low power consumption. A variable gain amplifier and an 11° trim bit are used to correct for the rms gain and phase errors at different operating frequencies. The phased array consumes 32 mW per channel and results in a gain of 10-19 dB at 76-84 GHz, a noise figure of 10.5 ±0.5 dB at 80 GHz and an rms gain and phase error <;0.8 dB and <;7.2 °, respectively, up to 81 GHz, and <;1.1 dB and 10.4° up to 84 GHz. The phased array also shows a channel to channel coupling of <; - 30 dB up to 84 GHz. To our knowledge, this work presents state-of-the-art on-chip performance at W-band frequencies.

57 citations

Patent
21 Feb 2007
TL;DR: In this article, a transducer array is subdivided into subarrays, each subarray having a number of adjacent array elements, and the low-beam-rate beams formed from each sub-array are upampled and interpolated prior to forming high-beam rate images.
Abstract: An invention for coherent array image formation and restoration is taught. The invention is applicable for both 2D and 3D imaging using either 1D or 2D arrays, respectively. A transducer array is subdivided into subarrays, each subarray having a number of adjacent array elements. All elements of each subarray transmit and receive in parallel. The signals received from each subarray are delayed and summed to form scan lines, or beams. The low-beam-rate beams formed from each subarray are upsampled and interpolated prior to forming high-beam-rate images. Depending on the subarray geometry, a subarray-dependent restoration filter is also applied to the subarray beams. The restored beams from each subarray are combined to form the final high-beam-rate image. The invention significantly reduces the front-end hardware complexity compared to conventional methods such as full phased array imaging with comparable image quality.

57 citations

Proceedings ArticleDOI
Edward I. Ackerman1, S. Wanuga1, D. Kasemset1, W. Minford2, N. Thorsten2, J. Watson2 
01 Jun 1992
TL;DR: In this article, a low-loss integrated 6-bit photonic time-delay unit was used in the demonstration of a photonic beamformer for eight subarrays of a 3-6 GHz phased array radar.
Abstract: The authors have developed a low-loss integrated 6-bit photonic time-delay unit to be used in the demonstration of a photonic beamformer for eight subarrays of a 3-6 GHz phased array radar. The current architecture for the electronic true-time-delay beamformer, and the proposed architecture for the equivalent photonic true-time-delay beamformer are presented. The 6-bit photonic time-delay unit design, showing the four 4*4 crossbar switch arrays realized using two 3-in LiNbO/sub 3/ substrates, is outlined. The time-delay unit fabrication is discussed. The results of the insertion loss and crosstalk measurements for each of sixty-four paths through the photonic time-delay unit are presented. >

57 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
2023373
20221,052
2021661
2020979
20191,266
20181,066