Felipe Vico-Bondia

A New Fast Physical Optics for Smooth Surfaces by Means of a Numerical Theory of Diffraction

A new technique to compute the physical optics (PO) integral is presented. The technique consists of a blind code that computes the different contributions (stationary phase points, end points, etc.) numerically. This technique is based on a decomposition of the surface into small triangles and a fast evaluation of each triangle by means of a deformation of the integration path in the complex plane. This algorithm permits a fast and accurate evaluation of the PO integral for smooth large surfaces. The CPU time is almost independent of frequency.

A 60-GHz LTCC rectangular dielectric resonator antenna design with characteristic modes theory

In this study, the theory of characteristic modes is used as the first time for the analysis and design of a wideband rectangular dielectric resonator antenna. The rectangular dieletric resonator antenna was excited by a microstrip feeder with a rectangular coupled slot. The antenna is designed for low-temperature co-fired ceramic fabrication, with Ferro A6-M material and for ISM-band at 60GHz. The proposed antenna has an impedance bandwidth of 33% for S11<;-10dB.

Algorithm for currents reconstruction using the FFT iterative method and a lattice of the spectrum

The knowledge of the equivalent currents of an antenna could become one of the most important aspects during its design process. This information can be obtained by knowing the currents obtained from the radiated field of the antenna. As this is usually measured in the near field region, is necessary to obtain a relationship between near field and equivalent currents. Basically, the process described in a previous paper obtains the far field from the near field measurements and with this far field calculates the plane wave spectrum. If this process is followed the maximum resolution achievable is 1 lambda. The reason for such a poor resolution is the use of only the visible spectrum. However, we need this non-visible spectrum to achieve a better resolution. For this reason we propose in this paper the combination of two techniques to obtain the non-visible spectrum. These techniques are the fft iterative method and the second technique is using the lattice of the spectrum to improve results. The use of both increases considerably the resolution of the reconstruction

Relation between Characteristic Modes and Complex Natural Resonances

In this paper Complex Natural Resonances of an infinite dielectric circular cylinder based on the PMCHWT formulation are presented. The relation between them and the Characteristic Mode resonances are explained. In addition, the reasons for different characteristic modes using different integral equations are explained. A connection between the resonances of series solution and integral formulations are carried out.

Geometrical representation infinitely smooth curves and surfaces for higher order computational electromagnetics

This paper shows a new interpolation technique to produce infinitely differentiable curves from a finite set of interpolating points. The technique will be very useful for the implementation of higher order numerical and asymptotical methods in computational electromagnetics. In this paper we show the 2D case (for curves). We will present a generalization for surfaces in the oral session during the symposium

Iterative Algorithm for Probe Calibration in Spherical Near-Field Antenna Measurement

Probe correction in spherical near-field measurements is a widely studied technique used to compensate for probe polarization and pattern effects. While the polarization compensation can be carried out in a straightforward way, the pattern compensation requires the knowledge of receiving coefficients which are not easily obtained. With this aim, several techniques, which are known as probe calibration techniques, have been introduced. However, none of them are accurate enough. This communication introduces an algorithm for the accurate computation of first-order probe receiving coefficients. It also shows how accurate gain may be determined by using these new coefficients.

Fast Physical Optics Method for 2D Rational Bezier Curves

This letter shows a fast technique to compute the physical optics (PO) integral of a rational Bzier curve. The algorithm is based on the path deformation technique. Good numerical results in terms of CPU time and accuracy are obtained.

Internal Natural Resonances Prediction Through the Theory of Characteristic Modes

This work was supported by the Spanish Ministerio de Economia y Competitividad under the project TEC2013-47360-C3-3P. This paper is a theoretical research article and contains no data.

New look of the mysteries of the characteristic modes

The theory of characteristic modes is being widely used for designing antennas (Y. Chang, and R. F. Harrington, 1977, Antennas and Propagation, IEEE Transactions on, 25(6), 789–795). Regarding to the design of dielectric objects there are still unknown aspects in the interpretation of their solutions. Previous works about characteristic Modes are published for conducting bodies and dielectric Bodies, but a difficulty to understand the solution using the surface integral equations based on Poggio-Miller-Chang-Harrington-Wu-Tsai (PMCHWT) formulation appears. It is also found that analyzing a dielectric body using different formulations, different results are obtained as the PMCHWT formulation provides more modes than those obtained using the Volume Integral Equation (VIE). What is observed is that the characteristic eigenvalues obtained with VIE are contained in the PMCHWT solution, resulting in the latter more solutions than in VIE. The observed difference is that PMCHWT provides two eigenvalues for each mode.

Integral equation methods at very low frequency

Integral equation methods at very low frequency are studied. Different problems such as the low frequency breakdown of the EFIE, the inaccuracy problem in the radiated electric field of the MFIE, the nullspace of the MFIE in the multiply connected case are studied.