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PHASIM, a sophisticated phased array antenna software simulator implemented in MATLAB 5.2
A sophisticated phased array simulator software package for the design and analysis of planar phased array antennas is presented. This simulator is coded in MATLAB version 5.2. Using MATLAB, numerical engineering problems can be solved in a fraction of time of time required by programs coded in FORTRAN or C. This paper addresses an assessment of the program, discusses its use and advanced farfield analysis capabilities

[Abstract]

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Overlapped feeds in multi beam reflector antennas
The performances of focal plane arrays that implement multibeam coverage from a single reflector antenna are usually reduced by conflicting requirements on the feed elements. Dense packing is required to minimize the beam separation, while typically large apertures provide the high feed directivity which in turn translates in low spill over losses from the reflector. In this contribution, the use of a dielectric superlayer to shape the radiation pattern of each feed, so that the spill over from the reflector is reduced without increasing the dimensions of each aperture, is discussed.

[Abstract]

3 

Powers synthesis of array antennas using the continuation method on far field phase distribution
We present a technique, based on the continuation method, to face power synthesis problems for array antennas. By using the least squares method (LSM), the power synthesis problem reduces to the minimization of an objective functional, which represents the square of the distance between the required and actual complex radiation pattern. Exploiting the GramSchmidt method (GSM) and the constrained minimization theory, the objective functional can be turned into a Lagrangian functional, which depends only on the radiation phase distribution. We use an iterative procedure for the optimization of the Lagrangian functional and we also introduce a continuation method to improve the reliability and robustness of the algorithm with respect to spurious solutions. Numerical simulations show better performance of the proposed algorithm, in terms of mean square error, than iterative least square synthesis (ILSS), although a slightly higher computational effort is required.

[Abstract]

4 

Dispersion properties of an array of slots etched at the interface between two infinite dielectric materials
An array of long slots, oriented along x, etched on a ground plane that separates two infinite dielectric materials constitutes the basic canonical problem investigated in this article. In a single slot structure, the direction of radiation and the attenuation constant could be directly linked to the dominant leaky wave pole (kxlw) that dominates the pertinent Greenâ€™s Function (GF) spectrum in the longitudinal direction, x. In a multi slot problem, the number of poles that appear in the GF is equal to the number (N) of slots composing the array and in view of this two problems arise. First, how to locate efficiently these N poles in the kx spectrum of the GF parameters. Secondly to asses which of these poles are significant, i.e. dominate the behaviour of the array.

[Abstract]

5 

EBG enhanced dielectric lens antennas for the imaging at submm waves
This paper presents a truly integrated antennas in mm and submm wave regimes can be realized by printing planar radiating elements in the focal plane of elliptical or extended hemispherical lens antennas. The elliptical shape of the lens gives high focusing properties provided that its eccentricity is properly related to its dielectric constant (e=1/epsiv1/2 r). In the frame of cooperation activity between TNO and SRON, the main purpose of this contribution is to present a new way to increase the directivity of the focal plane feeds typically used to excite such lenses. The driving reason for this effort is the desire to diminish the impact of the reflections at the dielectric air interface when these structures are proposed as focal plane imagers.

[Abstract]

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Properties of leaky waves supported by grounded dielectric superlayers and implications on the design of reflector feeds
The design strategy that uses dielectric superlayers with neighboring waveguides closed in matched loads constitutes a worst case scenario as far as the performance enhancement is concerned and finds applicability in radiometric imaging arrays. On the other side the design strategy that uses dielectric superlayers with neighboring waveguides closed in properly tuned reactive loads can be seen as best case scenario representative of a multi beam system for a telecommunication satellite with independent channels

[Abstract]

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PHASIM, an advanced phased array antenna software simulator
A sophisticated phased array simulator software package for the design and analysis of planar phased array antennas is presented. This package can accurately simulate the farfield characteristics of a large variety of planar phased array configurations in both the frequency and time domain. The simulator is coded in MATLAB version 5.3. Using MATLAB, numerical engineering problems can be solved in a fraction of time of time required by programs coded in FORTRAN or C. This paper addresses an assessment of the program, discusses its use and advanced farfield analysis capabilities.

[Abstract]

8 

A multi octaves directive dielectric lens: The Pyramid Antenna
Leaky wave antennas have been investigated for a long time and are typically an inexpensive solution for beam scanning antennas. We have designed a novel antenna topology, named the pyramid antenna, based on the broadband leaky concept. The pyramid antenna, currently covered by a patent application, has unparalleled bandwidth performances that can be briefly summarized as follows: 1) input impedance with low frequency dependence; reflection coefficients lower than 10 dB can be achieved over 1:8 bands; 2) Hplane radiation pattern is essentially frequency independent (on bands 1:10), while in the Eplane the directivity grows as a result of the lens shaping; 3) with respect to the competing Vivaldi type of radiators, the beam is purer in terms of polarization and more directive for comparable impedance bandwidths; 4) the pyramid antenna is suited for coplanar waveguide excitation which is the natural output of many integrated circuits; 5) pyramid antennas can be arranged in an array using a unique larger lens, if it is wished to use these lenses in an array configuration to scan the beam in the Fplane; in this configuration, the cross polarization levels would be outstanding

[Abstract]

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PHASIM, an advanced phased array antenna software simulator
A sophisticated phased array simulator software package for the design and analysis of planar phased array antennas is presented. This package can accurately simulate the farfield characteristics of a large variety of planar phased array configurations in both the frequency and time domain. The simulator is coded in MATLAB version 5.3. Using MATLAB, numerical engineering problems can be solved in a fraction of time of time required by programs coded in FORTRAN or C. This paper addresses an assessment of the program, discusses its use and advanced farfield analysis capabilities

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[Abstract]
