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Application and Validation of Design Tools for Antennas, IEE Colloquium on

Date 11 Jun 1993

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Displaying Results 1 - 10 of 10
  • Verification and validation of a diffraction program

    Page(s): 4/1 - 4/5
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (220 KB)  

    In the context of electromagnetics programs, verification is the checking of input data and validation is the checking of output results. These divide into several sections which partially correspond to the IEEE/ANSI definitions as follows (IEEE/ANSI terms in brackets): checking data entry for correct type and range (not allowed for in IEEE/ANSI); checking the program specification (error); checking the documentation (defect); checking for bugs (fault); and checking the algorithms (error). The author considers these and points out some of the problems which arise in attempting to verify or validate an electromagnetic program View full abstract»

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  • Problems concerning the validation of moment-method models of small aircraft in the HF band

    Page(s): 6/1 - 6/8
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (304 KB)  

    Considers an example of a moment-method modelling procedure which has been applied previously to other generic aircraft and antenna types. The overall aim of these studies is to provide a `recipe' for the prediction of airborne HF antenna system characteristics; the application of which will produce estimates of near as well as far-field dependent parameters which are credible and sufficiently accurate for engineering purposes. The procedure simulates the airframe as an electrically very fine wire-mesh (of mesh side length of the order of 1500 wavelength at 2 MHz) and uses NEC as the solution code. An important aspect of the studies described is that no empirically derived information of any kind is incorporated into the mathematical models constructed. Thus, true predictions are produced View full abstract»

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  • PLANAR: a computer program for planar array antenna design

    Page(s): 9/1 - 9/5
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (228 KB)  

    Whereas the computation of the radiation patterns for planar array antennas is relatively straightforward for simple elements and uniform illumination, the design of practical array antennas and the evaluation of candidate configurations are facilitated by computer modelling. The computer program PLANAR provides a method of modelling array antennas for a variety of element types and aperture distributions via a comprehensive set of input parameters. The program is interactive with facilities for defining, retrieving and editing sets of input parameters. The paper reviews the operation of PLANAR Version 5.0 and describes the types of array antenna which may be modelled. In addition, some comparisons between measured and predicted radiation patterns are also presented View full abstract»

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  • Application of generalised circular and rectangular mode matching techniques to the design of antennas

    Page(s): 1/1 - 1/6
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (284 KB)  

    An existing rectangular mode matching package `CORREC' previously developed for the analysis and design of pyramidal and corrugated horn antennas has been extended so that multiple rectangular apertures can be incorporated in a general fashion. Furthermore, ridged waveguide structures can also be included in the analysis. Such a generalised software package can be used to design mono-pulse feed horns, small horn arrays with associated feed networks, double ridged horns, corrugated and septum polarisers, couplers, filters and diplexers. An extension to quadruple ridged structures is currently being investigated View full abstract»

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  • The development of an optimal NEC model of a skeletal biconical antenna for use with antenna factor prediction

    Page(s): 5/1 - 5/8
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    A useful development of the modelling approach to antenna calibration is to accept that it is not practical to measure antenna factors directly and instead compare values of another antenna parameter, which can be measured accurately, with predictions derived from a model. One such parameter is drive-point impedance and, if a model can be developed which returns a drive-point impedance that agrees with measurement, the model may then be used with confidence to predict antenna factors. The paper shows how the drive-point impedance of a Schwarzbeck BBA9106 biconical antenna may be measured and then used as a guide to facilitate production of an accurate NEC model of the antenna. This model is then combined with the measured scattering parameters of the balun of the antenna in order to yield predicted antenna factors for the complete real antenna View full abstract»

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  • The validation and application of NEC and MININEC

    Page(s): 7/1 - 7/6
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (252 KB)  

    The computation of the radiation and scattering characteristics of antennas by means of the method of moments has now reached a stage of maturity after a decade or so of intensive use of various moment method codes. Arguably the most versatile of these, and certainly the best known is the Numerical Electromagnetics Code (NEC). Possibly equally well-known, though more limited in application, is MININEC. These moment method codes are discussed briefly with emphasis placed on their validation and application, particularly with vehicle mounted antennas. A novel procedure for synthesizing a required radiation pattern using a combined moment method-characteristic mode procedure is introduced View full abstract»

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  • Computer aided design of complex antennas

    Page(s): 3/1 - 310
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (380 KB)  

    Presents the use of several numerical methods for designing complex W-band reflector antennas, for use in a radar system, and an overmoded cavity fed helical antenna array. The paper shows the use of the moment method (MM) and time domain finite difference simulation (TDFDS) for determining the VSWR of an axi-symmetric splash-plate reflector, and the MM for designing a low VSWR axi-symmetric horn/subreflector antenna. A technique for improving the accuracy of the return loss of an open ended waveguide predicted by the MM is also presented. It demonstrates the use of TDFDS for designing an axi-symmetric dielectric cone subreflector, shows the design of a polarizing main reflector for use in a cassegrain antenna system, and presents the use of TDFDS for predicting the frequency response of an over-moded cavity fed helical antenna array View full abstract»

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  • Computer aided design of corrugated horns

    Page(s): 2/1 - 2/6
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (284 KB)  

    The conical corrugated horn has become the prime choice for use as a feed for high performance reflector antennas in communications, radar and remote sensing systems. This is partly because the radiation characteristics are ideal with good copolar pattern symmetry and low levels of cross polarisation. It is also because corrugated horns can be designed, using a computer, with a high degree of reliability. The paper describes the computer aided design of corrugated horns and discusses the methods used to design horns in terms of their accuracy, reliability and ease of use. The methods of validation are considered and the present position of the CAD of corrugated horns examined View full abstract»

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  • Design of a microstrip array antenna for a short-range two-way microwave system

    Page(s): 8/1 - 8/8
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (184 KB)  

    In the design of a microstrip planar array antenna, the individual patches can be in close proximity to each other, it is therefore necessary to consider the effect that the mutual coupling between the individual patches has on the performance of an antenna. The paper presents a method which takes into account this mutual coupling between the patches and how it affects the input reflection coefficient of each patch, antenna gain and sidelobe level View full abstract»

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  • IEE Colloquium on `Application and Validation of Design Tools for Antennas' (Digest No. 1993/147)

    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (12 KB)  

    The following topics were dealt with: generalised circular and rectangular mode matching for antenna design; CAD of corrugated horns; diffraction program verification and validation; NEC model of skeletal biconical antenna for antenna factor prediction; moment method models for HF band aircraft antenna; MININEC; microstrip antenna array; and PLANAR computer program View full abstract»

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