共查询到20条相似文献,搜索用时 593 毫秒
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《Vehicular Technology, IEEE Transactions on》2009,58(7):3137-3144
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随着相控阵技术的快速发展,数字相控阵系统对小型化、集成化、宽带化有了更高的要求。本文提出了一种收发全数字波束形成的新一代相控阵方案,研制了一套16通道的高集成度数字相控阵系统样机并完成了法向方向图测试。该方案采用高集成度射频前端,片内集成收发通道和频率合成器,相比传统分立器件方案更加紧凑。阵列整体采用瓦片集成方式,通过高密度垂直互联将天线阵面、校准网络、收发信道、波束形成器进行纵向集成,具备集成密度大、剖面低、通用性强、宽带特性好、易于扩展等诸多优点,具有良好的实用价值。 相似文献
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Beamforming experiment with a DBF multibeam antenna in a mobilesatellite environment 总被引:1,自引:0,他引:1
Miura R. Tanaka T. Chiba I. Horie A. Karasawa Y. 《Antennas and Propagation, IEEE Transactions on》1997,45(4):707-714
This paper describes a digital beamforming (DBF) multibeam antenna that incorporates a compact digital signal processor (DSP) engine, and the results of using it in a beamforming experiment receiving a satellite signal in a land-mobile environment. A considerable reduction in the scale of the DSP engine has been achieved by using field programmable gate arrays (FPGAs). To capture a satellite signal arriving from an unknown direction, a two-dimensional (2-D) spatial FFT signal processing provides orthogonal multibeam patterns on the broad side of a planar array antenna. The experimental results demonstrated the features of coarse acquisition and tracking of a signal arrival by selecting the strongest of the beams without assistance from direction finding sensors or microwave phase shifters. The DBF multibeam antenna will provide high-quality communications and increase traffic capacity if it is applied to high-gain mobile antennas or multispot-beam base station antennas in cellular or satellite mobile communications 相似文献
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园柱共形DBF天线阵中,由于天线阵中各个分天线不在同一平面上,边缘的分天线存在相当程度的绕射,这种绕射使得在进行DBF合成时,天线的方向图比较容易出现高的栅瓣.本文通过分析表明,低的副瓣与需要合成的部分分天线构成的圆心角以及分天线的反射板的尺寸有重要的关系. 相似文献
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In this paper, we investigate array calibration algorithms to derive a further improved version for correcting antenna array errors and RF transceiver errors in CDMA smart antenna systems. The structure of a multi‐channel RF transceiver with a digital calibration apparatus and its calibration techniques are presented, where we propose a new RF receiver calibration scheme to minimize interference of the calibration signal on the user signals. The calibration signal is injected into a multichannel receiver through a calibration signal injector whose array response vector is controlled in order to have a low correlation with the antenna response vector of the receive signals. We suggest a model‐based antenna array calibration to remove the antenna array errors including mutual coupling errors or to predict the element patterns from the array manifold measured at a small number of angles. Computer simulations and experiment results are shown to verify the calibration algorithms. 相似文献
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Self-survey calibration of meteor radar antenna arrays 总被引:1,自引:0,他引:1
Valentic T.A. Avery J.P. Avery S.K. Livingston R.C. 《Geoscience and Remote Sensing, IEEE Transactions on》1997,35(3):524-531
This paper presents the self-surveying technique for calibrating the antenna spacing, orientation, and phase errors in multiple receiver radar antenna arrays. Utilizing a set of source transmitters placed at known locations in the far-field of the array and measurements of the phase present at each antenna, the array's relative antenna locations and phase errors can be determined. The advantage of this technique is that the radar is used in its normal operating mode, providing an end-to-end calibration under true operational conditions. A self-survey calibration was performed with a meteor radar located at Sondre Stromfjord, Greenland, successfully mapping the array. The antenna positions were relatively close the expected locations, although the baselines were rotated approximately 5° from the true cardinal directions. The majority of the phase error was introduced by the receivers 相似文献
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Transmission bit rates are optimized for two-class traffic in variable spreading gain code-division multiple-access systems with antenna arrays. In an array antenna system, the interference levels experienced by the users belonging to different beams are not the same. Thus, it is not efficient to allocate the same rates to all the data users even though they belong to a cell. Considering this, an optimum rate allocation scheme is proposed for delay-tolerant data users. Additionally, we also propose the optimum rate allocation scheme for voice and data users when a packet scheduling scheme is considered. Numerical results show that, in array antenna systems, the proposed schemes considerably outperform the conventional scheme designed for omniantenna systems. 相似文献
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大型线阵自适应数字波束形成超低副瓣技术 总被引:5,自引:0,他引:5
自适应数字波束形成技术是现代阵列天线系统必须采用的关键技术。为了对付强有源干扰,现代相控阵雷达都必须具有自适应的干扰抑制能力。除了对抗有源干扰外,大部分雷达还要求具有强杂波背景下检测目标的能力,这就需要雷达天线具有低或超低副瓣电平。本文针对大型线阵,结合数字波束形成,讨论了在保证自适应干扰置零的前提下,如何控制自适应波束的副瓣电平,从而实现阵列系统的超低副瓣性能。 相似文献
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Directional power-based admission control for WCDMA systems using beamforming antenna array systems 总被引:2,自引:0,他引:2
A directional power-based admission control (AC) scheme is proposed for base stations deploying beamforming antenna arrays. The proposed AC algorithm is a natural extension of the conventional power based AC scheme for cells using standard sector antennas. The directional scheme takes the load per beam/direction into account in the AC decision, so the cell load is controlled in accordance with the spatial filtering gain provided by using beamforming antenna arrays. The scheme is tested by means of Monte Carlo simulations in a multicell wideband code division multiple access (WCDMA) network, where users with different bit rates are present. The obtained results demonstrate that the directional power based AC scheme allows a higher traffic load in cells using beamforming antenna arrays without jeopardizing the stability of the network. Application of a four element antenna array is found to provide a capacity gain of a factor 2.7 for a network with many low bit rate users, while the gain is reduced to a factor 2.3 for traffic scenarios with a mixture of high and low bit rate users. 相似文献
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For pt.I see ibid., vol.46, no.3, p.397-406 (1998). A new expansion scheme is introduced to solve the integral equations describing the mutual coupling in microstrip arrays. The scheme is based on the fact that at larger distances the Green's functions in the stratified dielectric medium of the antenna structure can be approximated using analytical expressions. This allows one to describe the waves propagating between the elements thus causing mutual coupling with a small number of parameters. Since only these parameters have to be determined, the resulting number of unknowns is much smaller than with conventional rigorous techniques. The accuracy of the scheme is illustrated by a comparison of measured and calculated data for both a two-element and a linear eight-element microstrip array antenna 相似文献
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一种新的数字阵列雷达接收机技术 总被引:2,自引:1,他引:1
高速ADC和先进DSP器件的进展使数字波束形成智能天线的实现成为现实。在传统的M单元天线阵系统中,每一单元都有各自的接收通道和ADC,设备量大。文中提出了一种适合于多通道数字阵列雷达接收系统的新型数字接收机结构,其主要思想是基于多个不同信号的带通采样原理实现数字阵列雷达接收机,新接收机结构使IF接收通道和基带采样ADC显著减少,功耗大大降低。阐述了数字阵列接收的数据模型和工作原理,分析了多信号带通采样信号频率和采样率的关系,给出了采样率选取的约束条件。新接收机在降低设备量的同时,还减小了接收系统通道间幅一相不一致性失真。 相似文献
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High Resolution Wide Swath (HRWS) Synthetic Aperture Radar (SAR) often suffers from low Signal-to-Noise Ratio (SNR) due to small transmitting antenna, especially in phased array antenna systems. Digital Beam Forming (DBF) based on Single Input and Multiple Output (SIMO) achieves receiving array gain at the cost of increasing data rate. This letter proposes a new HRWS SAR method, which employs intra-pulse null steering to get receiving gain in elevation and decrease the data rate, and Multiple Input and Multiple Output (MIMO) using Space-Time Block Coding (STBC) in azimuth to get transmitting gain and receiving array gain simultaneously. The feasibility is verified by deduction and simulations. 相似文献
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《Antennas and Propagation, IEEE Transactions on》2006,54(10):2820-2826
A beamforming approach for phased arrays on vibrating apertures is proposed. The essence is to dynamically calibrate the antenna element position errors due to aperture vibrations. This is achieved by estimating element positions through the aid of a few near field reference sources attached to the antenna. The reference sources need to be mounted on rigid frames and be impervious to vibrations. The estimated position information is then substituted into the beamforming process to correct the distorted pattern of the antenna array. To validate the proposed concept, a 5.8 GHz eight-element array with artificially displaced element positions is built to emulate the vibration effect. The proposed calibration approach gives, a close estimate of position errors with deviations under 4% of the free space wavelength. Based on the estimated information, an array pattern with desired features is constructed. 相似文献