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Adaptive Antennas, IEE Colloquium on

Date 8 Jun 1990

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  • IEE Colloquium on `Adaptive Antennas' (Digest No.098)

    Publication Year: 1990
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (72 KB)  

    The following topics were dealt with: adaptive antenna architecture and applications; adaptive nulling techniques; radar systems; systolic array processor; beamforming; array pattern stabilisation; transputer-based sonar DF system View full abstract»

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  • Architecture and applications of high performance adaptive antenna equipment

    Publication Year: 1990 , Page(s): 1/1 - 1/6
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (240 KB)  

    The author considers a high performance architecture for the Antenna Control Unit part of an adaptive antenna system which has been successfully applied to a number of diverse applications. A brief justification for the architecture along with results and application examples are presented View full abstract»

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  • MESAR adaptive nulling/digital adaptive architectures

    Publication Year: 1990 , Page(s): 2/1 - 2/4
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (188 KB)  

    MESAR (multifunction electronically scanned adaptive radar) is the UK active phased array demonstrator programme. It employs advanced digital adaptive beamforming and has demonstrated the full potential of adaptive nulling technology. The author describes the MESAR adaptive nulling architecture. The MESAR application is then used to compare two parallel approaches to digital adaptive beamforming. The performance of a systolic array of specialist devices performing QR decomposition is compared with a coarse grain array of more standard devices employing a covariance matrix based algorithm. It is found that the coarse grain approach has significant advantages View full abstract»

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  • Integrated digital adaptive antennas

    Publication Year: 1990 , Page(s): 6/1 - 6/6
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (424 KB)  

    The authors consider the philosophy behind the design of high performance digital adaptive antenna processors for future communications and radar applications. The advent of digital radio technology will mean that digital beamforming techniques will become more universal, particularly for communication applications. In such systems, the concept of an integrated adaptive antenna will become a reality since the adaptive processor will simply be an extension of the digital signal processing performed by the digital receiver design. The authors present a design concept which uniquely exploits systolic array technology and complex VLSI circuitry to provide a highly integrated adaptive beamformer architecture capable of extremely rapid adaptation in real-time. A prototype unit is presently being developed at STC using a VLSI node chip processor which has been designed as part of the VHPIC application demonstrator programme View full abstract»

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  • Adaptive nulling techniques for look-down radar systems

    Publication Year: 1990 , Page(s): 3/1 - 3/3
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (132 KB)  

    Strong clutter has been shown to have a significant effect upon the performance of a conventional adaptive nuller. Two methods for resolving this problem have been presented. The first of these uses digital FIR filtering to remove the clutter return signals prior to adaptive nulling. The second method uses displaced phase centre antenna (DPCA) processing to remove the clutter prior to adaptive nulling. Of the two, the method using DPCA processing gives a more elegant solution since it integrates high performance adaptive clutter cancellation with adaptive nulling in a relatively simple architecture View full abstract»

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  • Stabilisation of adaptive array patterns by signal space projection

    Publication Year: 1990 , Page(s): 5/1 - 5/3
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (220 KB)  

    Adaptive array (and sidelobe canceller) patterns are found to fluctuate considerably from one set of data to another, when there are degrees of freedom to spare, unless a very considerable amount of data integration is performed. A highly effective cure for this effect is to determine a basis for the signal space for the system and project the normally obtained optimum weight vector into the signal space. The resultant vector gives patterns which are virtually identical on successive data blocks. The basis need not be of eigenvectors and can be obtained by quite simple processing of the data View full abstract»

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  • A systolic array processor for MVDR beamforming

    Publication Year: 1990 , Page(s): 4/1 - 4/2
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    The authors describe a novel systolic array which can efficiently compute the minimum variance distortionless response (MVDR) from an array of antenna receiver elements in a rapidly changing signal environment. The MVDR beamforming problem amounts to minimising, in a least squares sense, the combined output from an antenna array subject to K independent linear equality constraints each of which corresponds to a chosen `look direction' The constraints are independent in the sense that, for each new vector of received data samples, it is necessary to compute the minimum array output subject to each constraint in turn. This involves the solution of K independent, but closely related, least squares minimisation problems View full abstract»

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  • High resolution sonar DF system

    Publication Year: 1990 , Page(s): 7/1 - 7/3
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (156 KB)  

    The authors present the results of some experiments carried out to implement certain high resolution DF algorithms on a transputer-based sonar system. These experiments were at a reservoir using a 10 element array working at a frequency of 40 kHz. In this paper two main algorithms, the Capon method or the so called maximum likelihood method (MLM) and the multiple signal classification method (MUSIC), are compared with the conventional beamformer View full abstract»

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