Bird, TS 1987, 'EXACT SOLUTION OF OPEN-ENDED COAXIAL WAVEGUIDE WITH CENTRE CONDUCTOR OF INFINITE EXTENT AND APPLICATIONS.', IEE Proceedings H: Microwaves, Antennas and Propagation, vol. 134, no. 5, pp. 443-448.
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A thin-walled coaxial waveguide open at one end and having the center conductor extending to infinity in the forward axial direction is studied for asymmetric mode excitation. After satisfying the boundary conditions on the structure the resulting equations are solved exactly by the Wiener-Hopf technique using Weinstein's approach. From this solution expressions are obtained for the coefficients of the modes excited in the waveguide and for the far fields radiated from the open end of the guide. Explicit results are given for the reflection coefficient and for far-field radiation patterns for TE//1//1 mode excitation. Experimental results demonstrate the validity and accuracy of the solution. Using these results we assess the performance of a thin-walled coaxial waveguide for possible application as a self-supporting feed for a reflector.
Bird, TS 1987, 'Mutual coupling in finite coplanar rectangular waveguide arrays', Electronics Letters, vol. 23, no. 22, pp. 1199-1201.
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Mutual admittance expressions are given for all possible combinations of mode coupling in an array of identical collinear rectangular waveguides opening into an infinite ground plane. Specific results are presented for the worst case of E-plane coupling between identical square waveguide to show that significant high-order mode excitation can occur. Some of these modes are a source of crosspolarisation, making mutual coupling important to the prediction of the crosspolar pattern of a rectangular waveguide array. © 1987, The Institution of Electrical Engineers. All rights reserved.
BIRD, TS 1987, 'TE11 MODE EXCITATION OF FLANGED CIRCULAR COAXIAL WAVE-GUIDES WITH AN EXTENDED CENTER CONDUCTOR', IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION, vol. 35, no. 12, pp. 1358-1366.
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Bird, TS & James, GL 1987, 'ANTENNA RESEARCH & DEVELOPMENT IN AUSTRALIA: A PROGRESS REPORT.', Journal of Electrical and Electronics Engineering, Australia, vol. 7, no. 4, pp. 227-233.
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Antenna research and development undertaken in Australia in the five-year period since 1982 is briefly outlined. Over 20 institutions and industries are included in this review and a representative sample is given of papers published in the period.
ZIOLKOWSKI, RW 1987, 'EXACT SOLUTION OF THE SOMMERFELD HALF-PLANE PROBLEM - A PATH INTEGRAL APPROACH WITHOUT DISCRETIZATION', JOURNAL OF ELECTROMAGNETIC WAVES AND APPLICATIONS, vol. 1, no. 4, pp. 377-402.
Ziolkowski, RW 1987, 'New electromagnetic resonance effects associated with cavity‐backed apertures', Radio Science, vol. 22, no. 4, pp. 449-454.
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A number of canonical problems that describe the coupling of electromagnetic fields through apertures into enclosed regions have been solved. The scattering data generated by these cavity‐backed aperture solutions share a common property: they are dominated by resonance features closely connected to the presence of the cavity. The behavior of these cavity‐backed aperture resonance features has been characterized for variations in frequencies, angles of incidence, look angles, aperture sizes, and interior object properties. It has been found that the scattering cross sections contain information about the interior of the cavity. Copyright 1987 by the American Geophysical Union.
ZIOLKOWSKI, RW & GRANT, JB 1987, 'SCATTERING FROM CAVITY-BACKED APERTURES - THE GENERALIZED DUAL SERIES SOLUTION OF THE CONCENTRICALLY LOADED E-POL SLIT CYLINDER PROBLEM', IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION, vol. 35, no. 5, pp. 504-528.
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ZIOLKOWSKI, RW & JOHNSON, WA 1987, 'ELECTROMAGNETIC SCATTERING OF AN ARBITRARY PLANE-WAVE FROM A SPHERICAL-SHELL WITH A CIRCULAR APERTURE', JOURNAL OF MATHEMATICAL PHYSICS, vol. 28, no. 6, pp. 1293-1314.
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Ziolkowski, RW & Johnson, WA 1987, 'Pseudodecoupling ansatz for electromagnetic aperture coupling in three dimensions', Radio Science, vol. 22, no. 2, pp. 169-174.
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Hertzian potentials are commonly used to describe the scattering of electromagnetic waves in three dimensions. However, when apertures are present in the scattering object, mixed boundary conditions arise and the TE and TM modes of the scattered field become coupled. Numerous attempts to decouple these TE and TM modes have led to solutions of Maxwell's equations which fail to satisfy Meixner's edge conditions. It has been found that by introducing additional gauge potentials which are homogeneous solutions of the boundary condition equations, a pseudodecoupling of the TE and TM modes can be achieved while still satisfying Meixner's edge conditions. Copyright 1987 by the American Geophysical Union.
Bird, TS 1987, 'RING-SLOT FLANGE FOR REAR-RADIATING CUP FEEDS.', IEEE Antennas and Propagation Society, AP-S International Symposium (Digest), pp. 672-675.
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The author describes the improvement in gain and cross-polar performance that results from the addition to a cup of a flange containing ring-slots. The aperture efficiency of a paraboloidal reflector with a cup feed is considered. A highly accurate model for the radiation from a cup feed is used in the design.