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Analysis of a probe fed circular patch antenna etched on electrically thick substrate is presented. The feed probe is considered to be the primary source of radiation, which induces currents on the patch surface. The patch is assumed to be a perfect conductor so that the tangential electric field is zero on the patch surface. The total reaction on the patch surface (sum of self reaction of the patch...
The Generalized Multipole Technique is the base of the MMP (Multiple MultiPole) codes. This technique will be presented in the most simple and basic way with a brief historical introduction followed by the main principles. Then, the graphic editor and the structure of the codes will be presented, A short word on the implementation and parallelization of the codes will be given (INMOS Transputers,...
The influence of the ground on the fields of antennas has been discussed sporadically in the literature for many years. In most propagation calculations, it is assumed that the transmitting antenna has a fixed di-pole moment and the ground is taken to be a perfect conductor or possibly a homogeneous imperfectly conducting half-space. In practice, however, some kind of ground system is employed. Usually...
With the advent of digital cellular radio, interest has been renewed in the area of mobile antenna diversity. This paper presents the results of experiments performed at NovAtel investigating the improvement in audio quality of typical cellular calls due to space diversity with a simple combining scheme.
This paper presents the development of a simple and effective plane absorbing boundary for the FDTD method. This absorbing boundary produces virtually no reflection at the tuning frequency, accomodates arbitrary incidence angle, and remains very local. The algorithm requires the knowledge of the field values at grid points lying only one space increment away from the absorbing boundary. The algorithm...
A theoretical study is presented of the input impedance and bandwidth of biconical microstrip antennas asymmetrically excited by a coaxial probe feed. The antenna consists of a conducting cone cap on a grounded cone separated by an electrically thin dielectric. The structure is of biconical type. The analytic results for zero order modes (including the special case, TEM mode) of the biconical structure...
The reflected and transmitted field vectors resulting from an arbitrarily incident electromagnetic wave on a slab of an inhomogeneous dielectric are rigorously derived. The incident wave is expressed as a spectrum of infinite number of plane waves of different amplitude and phase. The slab is bounded between the two planes z=0 and z=d and the dielectric material is characterized by μ0 and ∊ where...
During the past two years the Antennas/Propagation group at NovAtel Communications Ltd has developed a unique automated Antenna Test Range (ATR). This facility is capable of measuring the entire far field radiation pattern of small antennas and displaying the results in two and three dimensional polar plots. This is accomplished by connecting a battery powered transmitter to the Antenna Under Test...
The time reference scanning beam Microwave Landing System (MLS) is an air derived system, whereby airborne receivers decode continuous ground system data to provide guidance information indicating vertical and lateral displacement from a selected flight profile. It is expected that MLS, within ten years, will replace the Instrument Landing System (ILS) as a precision landing aids to aircrafts in most...
In this paper Kottler's formula is extended to treat the radiation from a fictitious and enclosing convex regular surface of zero thickness where we know the electromagnetic field distribution at each point. When the product of the two main radius of curvature is lower than the square of the free space wavelength, the field calculated with Kottler's formula may be wrong. Acorrection term applied to...
Parallel plate EMP simulators can be made from two sets of parallel wires to reduce wind loading, weight, and icing problems. The available literature on this kind of simulator construction is inadequate for the prediction of such basic design information as characteristic impedance and field enhancement.
We propose to investigate printed circuit applicators for biomedical applications: the microstrip-microslot and the microstrip applicators laid on multilayered lossy media and covered or not with a superstrate. We want to get their fundamental characteristic parameters: the complex propagation constant (relative effective permittivity ∊reff, attenuation α), the associated characteristic impedance...
Different radiation formulas are compared for the case of a rectangular microstrip patch antenna, either on an infinite substrate (Fig. la) or on an infinite ground plane with the substrate truncated at the boundary of the patch (Fig. lb). For both the infinite and truncated substrate cases the electric current model is compared with the magnetic current model using the dominant-mode assumption. A...
A dual polarized microstrip patch array is being developed for use in a polarimetric synthetic aperture radar system. This paper presents an analysis and empirical results for the linear array in the elevation plane which will be replicated 96 times to form a 2.5m × 0.5m planar array. The vertical and horizontal polarizations of the linear array are series and aperture fed respectively. As a result...
A concept/technique is described for reducing the effects of multipath contamination of the main beam, by using antenna phase center diversity. Results of a concept validation test are given.
The Transmission-Line Matrix (TLM) method, originated by Johns and Beurle [1] is based on equivalent circuit models of Maxwell's equations and has been used extensively to analyze electromagnetic field problems [2]. In this paper the application of the TLM method to two dimensional electromagnetic scattering problems is investigated. The configuration of the mesh is the same as that used in Finite-Difference...
In this paper, the effect of amplitude and phase errors as well as amplifiers and phase shifters failures on a phased array performance is investigated. It is found that random phase errors and phase shifters failures are dominant factors, they influence the peak sidelobe level, pointing angle accuracy, directive power and the half power beamwidth.
The scattering properties of a homogeneous elliptic cylinder with a dielectric or magnetic coating are investigated analytically. The method of separation of variables is used to determine, exactly, the field distributions in each region for the transverse electric (TE) excitation. The technique can be easily extended to handle any number of layers. The behavior of the scattered field in the far zone...
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