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IEE Proceedings H - Microwaves, Antennas and Propagation

Issue 2 • Date April 1987

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Displaying Results 1 - 20 of 20
  • Planar symmetrical six-port junction

    Publication Year: 1987, Page(s):109 - 115
    Cited by:  Papers (9)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (549 KB)

    A planar symmetrical six-port junction is described. The application of this junction to the technique of six-port impedance measurement is shown. The impedance measurement technique gives rise to three q-points which exhibit the characteristics of lying on the unit circle of the complex plane and having angular separations of 120¿¿ View full abstract»

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  • Using the least-squares boundary residual method to model the symmetrical five-port waveguide junction

    Publication Year: 1987, Page(s):116 - 124
    Cited by:  Papers (13)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (1073 KB)

    Using the least-squares boundary residual method, an electromagnetic model of the symmetrical 5-port waveguide (E-plane coupled) junction is developed. The numerical results obtained from the computer model are subjected to a series of computational and experimental tests and found to be accurate to within ¿¿1%. These theoretical data can aid the design of a symmetrical 5-port waveguide junction f... View full abstract»

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  • Noise parameter transformations of interconnected two-port networks

    Publication Year: 1987, Page(s):125 - 129
    Cited by:  Papers (1)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (328 KB)

    Calculations of noise parameters of interconnected two-port networks tend to be very lengthy. Furthermore the transformations are very involved which makes them hard to interpret. The paper presents a method by which these calculations may be simplified. By superposition the calculation is divided into two steps of which the second is independent of the type of interconnection involved. In this wa... View full abstract»

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  • Cylindrical surface waveguide modes using a surface impedance dyadic method

    Publication Year: 1987, Page(s):130 - 138
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (813 KB)

    The fields and characteristic parameters of nonradiating modes of a dielectric-coated wire with an intervening airgap are derived using a surface impedance dyadic method. This method shows several advantages and provides a straightforward method for working out the characteristic equation, cutoff conditions, far-from-cutoff conditions and field coefficients. Important results about the hybrid natu... View full abstract»

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  • Design off quarter-wave plates using a cavity-resonator technique

    Publication Year: 1987, Page(s):139 - 144
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (615 KB)

    The design of a compact quarter-wave plate requires a knowledge of both the phase constants of its split normal modes and those of its dual degenerate coupled modes. It also requires a statement of its scattering matrix. The purpose of the paper is first to formulate this problem and secondly to provide an experimental database for the phase constants of one type of plate using a resonator techniq... View full abstract»

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  • Coaxial line to stripline directional coupler

    Publication Year: 1987, Page(s):145 - 150
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (706 KB)

    Electromagnetic coupling between a coaxial line and a stripline is studied using the generalised version of Bethe's aperture coupling theory. The equivalent electric and magnetic dipole moments accounting for the coupling of one line with the other through the aperture are determined using a novel but simple and physically illuminating application of the image theory. The analytical expression obt... View full abstract»

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  • Mode matching method for determination of the resonant frequency of a dielectric resonator placed in a metallic box

    Publication Year: 1987, Page(s):151 - 155
    Cited by:  Papers (5)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (465 KB)

    A method for the determination of the resonant frequency of a cylindrical dielectric resonator inserted into a cylindrical metallic box is presented. The method can be applied to asymmetrical structures. View full abstract»

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  • Integral analysis off hybrid coupled semiconductor phase shifters

    Publication Year: 1987, Page(s):156 - 162
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (712 KB)

    A complete analysis of a hybrid coupled phase shifter which includes the performance of the coupler is presented. Closed-form solutions have been derived for the reflected and transmitted signals in a hybrid coupler whose coupled ports are reflectively terminated. With the help of these expressions, a complete branch-line hybrid coupled phase-shifter circuit, along with the coupler, is analysed. T... View full abstract»

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  • Accurate numerical solution of coupled integral equations for microstrip transmission line

    Publication Year: 1987, Page(s):163 - 168
    Cited by:  Papers (1)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (692 KB)

    A direct and numerically efficient method for calculating frequency-dependent phase constants of even and odd hybrid modes of the microstrip transmission line is described in the paper. The convergence of the numerical solutions obtained is investigated. It is shown that the accuracy of these solutions depends highly on the way in which the truncation of the infinite matrix equation is performed. ... View full abstract»

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  • Millimetre-wave propagation through hydrocarbon flame

    Publication Year: 1987, Page(s):169 - 173
    Cited by:  Papers (1)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (536 KB)

    The propagation of microwave and millimetre-wave signals through flame has been investigated with reference to the reliability of future communications systems on deep-water oil production platforms. The results show that the 0.5 m thick flame investigated produced little attenuation,>0.5 dB at frequencies between 37 and 210 GHz, but that scintillation effects were enhanced by the presence of f... View full abstract»

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  • Fast signal acquisition by an adaptive antenna moving in a multipath field

    Publication Year: 1987, Page(s):174 - 180
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (860 KB)

    An adaptive antenna algorithm is described which acquires a signal of unknown direction in the presence of uncorrelated interference and coherent multipath by using a sequential power search procedure on a small number of stored vector samples of the field. A set of candidate weighting vectors is generated, one of which, when used to filter the antenna circuit, will usually produce the desired sig... View full abstract»

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  • Em lens waveguide transition

    Publication Year: 1987, Page(s):181 - 184
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (501 KB)

    In the paper, a lens waveguide transition section between cylindrical coaxial waveguides of different size is specified. If it is required that transmission-line impedances be matched to the lens impedance and also that the transit time for TEM waves following different paths be equal, then an initial-value problem arises. Solutions to this problem then determine the lens geometry and material. View full abstract»

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  • Microstrip feeds for prime focus fed reflector antennas

    Publication Year: 1987, Page(s):185 - 193
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (831 KB)

    The use of microstrip radiators as feeds for reflector antennas is of great current interest, as they can result in reduced feed volume and weight, and such aspects are important in a number of applications, including satellite systems. In the paper the performance characteristics, and in particular the radiation pattern symmetry and cross-polarisation, together with bandwidth and efficiency, of s... View full abstract»

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  • Circularly polarised radiation from singly fed equilateral-triangular microstrip antenna

    Publication Year: 1987, Page(s):194 - 198
    Cited by:  Papers (14)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (496 KB)

    The paper presents an equilateraltriangular microstrip antenna (MSA) that can produce circularly polarised waves with a single feed. Theoretically predicted results, such as the operating frequency and feed location with which good circularly polarised radiation can be obtained, are compared with experimentally obtained results. The calculations for the axial ratio and the radiation pattern are al... View full abstract»

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  • Offset spherical reflector with a low sidelobe radiation

    Publication Year: 1987, Page(s):199 - 204
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (539 KB)

    This paper presents a design study of an offset antenna which employs a spherical main reflector and phase correcting subreflector. Detailed predictions are compared with the measured performance of a prototype design. The antenna provides a sidelobe envelope well within the US Federal Communications Commission specification for small earth stations. View full abstract»

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  • Analysis of a class of symmetrical thin-plate triangular antennas

    Publication Year: 1987, Page(s):205 - 210
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (687 KB)

    A method is presented for the analysis of a class of symmetrical thin-plate triangular antennas. The antenna current distribution is obtained by solving the two-potential equation by means of the point-matching method with a polynomial approximation for the current distribution. The edge effect is taken into account by introducing line currents at the edges. To obtain an accurate and stable soluti... View full abstract»

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  • Feed-point reflection coefficient of an element in a scanning antenna array: time-domain measurements

    Publication Year: 1987, Page(s):211 - 215
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (754 KB)

    A linear array of five radiating apertures with separate feed ports is used to illustrate the variation of reflection coefficient at the central port with variation of scan angle from zero to 54° over the frequency range from 0.6 to 6 GHz. Two different time-domain methods, showing excellent agreement for the determination of reflection coefficient, are employed. Indirect determination, by summin... View full abstract»

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  • Radiation-pattern control of Cassegrain antennas

    Publication Year: 1987, Page(s):217 - 222
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (750 KB)

    Using the results of a theoretical analysis of the radiation pattern of Cassegrain antennas, the paper discusses the requirements imposed by the most recent Consultative Committee on International Radio (CCIR) recommendations for the maximum-allowable sidelobe level applicable to earth-station antennas with D/¿ > 150 (D being the diameter of the main reflector). Also considered are the require... View full abstract»

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  • Technical memorandum. WRD 200 90° waveguide differential phase-shift section

    Publication Year: 1987, Page(s):223 - 225
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (236 KB)

    A 90¿¿ phase bit is a classic element in circuit theory. The paper describes the experimental development of a 90¿¿ differential phase-shift section in WRD 200 ridge waveguide with a phase deviation of ¿¿3¿¿ over the full 2¿¿4 GHz band and an insertion loss of 0.5 dB ¿¿ 0.1 dB. View full abstract»

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  • Technical memorandum. Cutoff frequencies of waveguides of arbitrary cross-section: optimisation of kohn-kato bounds

    Publication Year: 1987, Page(s):226 - 228
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (226 KB)

    It is shown that the results obtained by the Kohn-Kato enclosure theorem in the case of hollow-piped waveguides of complicated boundary shape can be optimised if an exponential unknown parameter is included in the co-ordinate functions which satisfy identically the governing boundary conditions, once the given domain is transformed into a unit circle. View full abstract»

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