A novel analysis of a rectenna circuit with iterative method

In this paper, we present the WCIP iterative procedure (wave concept iterative procedure) for solving continuity conditions in terms of waves rather than in term of tangential fields providing a mixed resolution in spatial and spectral domain taking the best advantage of each resolution domain and lower computation time. The spiral inductor with patterned ground shield is taken as an example of multi-layer structures; the results are in reasonably good agreement with the experimental data.

In this paper, a rectangular metallic ring FSS (Frequency Selective Surfaces) with parallel metallic strips for multi band applications are characterized by the WCIP (Wave Concept Iterative Procedure) method. The proposed FSS structures are made of metallic elements that are simultaneously independent in the spatial domain and uncoupled in the spectral domain. Thus the FSS multiband behavior can be achieved only by a building process based on independent metallic elements in both domains. The resonant characteristics of the proposed FSS are determined. The structure shows three resonant frequencies when the incident wave is x-polarized and three resonant frequencies when the source is polarized in the orthogonal direction. A variation in the length of the strips and the rectangular ring allows a fine tuning in the FSS resonant frequencies to give raise to tuned bandwidths. The suppression of a resonant frequency can be insured either by the elimination of the responsible metallic strip or by the insertion of a PIN diode switch. Three FSS structures are manufactured and characterized. The FSS bandwidth can be enhanced in both perpendicular FSS exciting source directions by only varying the strips lengths and the ring dimensions to the corresponding resonant frequencies. A good agreement is obtained when the WCIP results are compared with the simulations of COMSOL Multiphysics software and experiment.

The wave concept iterative procedure (WCIP), already improved for planar circuits, is developed in this paper for cylindrical structures. The WCIP method has been applied with success to the scattering of an E‐polarisation plane wave on cylindrical strips. The results are in good agreement with previous works in the literature, and the calculation time involved is quite reasonable. © 2003 Wiley Periodicals, Inc. Microwave Opt Technol Lett 38: 403–406, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.11074

We have studied a frequency selective surface (FSS) for a U-shaped geometry by a method called the Wave Concept Iterative Procedure (WCIP). The development of this method based on Fast modal transformation (FMT), for the FSS frequency response is presented in the results of a single resonance obtained by the WCIP method exhibit a resonance frequency at 5.6 GHz with a bandwidth of 2.75 GHz, when the structure is excited in the x direction by a plane wave at normal incidence, a resonance frequency at 11.6 GHz with a 414.61 MHz band when the structure is excited in the y direction. The simulation of the results obtained by the WCIP method are compared to the HFSS results and a good agreement is to score.

The work presented here introduces lumped elements to an iterative method based on the wave concept combined with the two-dimentional fast Fourrier transformation algorithm known as fast modal transformation (FMT). We extend this method to the analysis of microwave-distributed circuits containing passive or active, linear or nonlinear lumped elements which are characterized by their surface impedance as defined in this article. Simulation results of varactor-tuned filter and phase-shifter circuit examples are compared with the measurement results. Good agreement between simulated and experimental results validates the use of the iterative method for the analysis of planar circuits, including lumped elements. © 2003 Wiley Periodicals, Inc. Int J RF and Microwave CAE 13: 269–275, 2003.

Computer programs for simulation of microwave structures are becoming accessible. However, to understand electromagnetic fields behavior and to comprehend the numerical model limitations, a solid theoretical basis and computational expertise to enable the implementation of the own programs remains indispensable. The wave concept iterative procedure, WCIP, is a numerical technique easy to understand, that can be implemented without great efforts. In this work the WCIP is applied to analysis of frequency selective surface, FSS, with Koch Island patch elements. Obtained numerical results are compared to others obtained by the use of Ansoft Designer <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">™</sup> software and to experimental ones.

This paper introduces a new formulation of the iterative wave method to study the DGS `Defected Ground Structure' technique applied to the SIW `Substrate Integrated Waveguide' technology. This makes possible the analysis of arbitrary forms of the ground and circuit planes and the{non-conventional} metallic via holes configuration. The study is based on the recursive relationship of longitudinal reflected and incident waves in both spatial and spectral domains. The unconditional stability and the convergence of the method were well verified. In fact, we will validate the proposed approach by the analysis of a SIW filter with folded DGS. The numerical results are in good agreement with those obtained by the HFSS software `High-Frequency Structure Simulator'. Moreover, the presented method shows a considerable reduction in the required computational resources, which proves the high effectiveness of our method.

This paper presents a new electromagnetic modeling of a via-hole using a Wave Concept Iterative Procedure. There are specific TM modes associated with the insertion of the via-hole influencing the incident and reflected waves, called the "via's modes". The formulation and results are presented considering the influence of one and two via's mode. The advantage of the model presented is the possibility to simulate planar circuits with a layer and a via-hole considering the effects of the field that propagates around the via.

We studied the behavior of two-dimensional periodic circuit which acts as a lens which transforms cylindrical excited waves to a plane waves. The WCIP method (Wave Concept Iterative Procedure) is combined to a graphic Paint interface to analyze a circular shaped lens by showing the spatial voltage distribution through the total circuit. The results of simulation are illustrated by those given in the literature.

The Wave Concept Iterative Procedure is validated for multi-layered substrate with frequency dependent and negative index media. By shifting the plasma frequency, reconflgurable fllter design is proposed with a center frequency tunability of 25%. Sensitivity to collisional plasma is proposed.

5 - Iterative schemes and convergence analysis

Comparing circuit simulation results, an analytical model for the efficiency of single shunt rectenna circuits is developed. The model estimates the DC output power and loss power in rectenna circuits and gives good agreements with circuit simulation results. With this model, the effect of signal frequency and the diode capacitance is clarified.

Open-region problems of scattering by conducting cylinders are solved employing finite element method (FEM). The radiation condition for the open-region problem is enforced by the field integral equation solution approach using Green's function through an iterative procedure. At each iteration cycle, the induced currents on the scatterer are evaluated and their scattered fields at the terminating surface are calculated by the field integral equation. Using this iterative procedure, the computational domain ran be terminated very closely to the scatterer, yet keeping the sparseness of the FEM matrices. This iterative method is applied for several TE scattering problems of conducting cylinders. The numerical results are presented and compared with the results of other methods to illustrate the applicability and accuracy of this method.

This paper proposes an efficient and fast analysis of substrate integrated waveguide (SIW) components using a new approach of the iterative method called WCIP, i.e. “Wave Concept Iterative Process”. This method is based on the iterative resolution of waves between two domains. The first is the spectral domain. We use the Floquet–Bloch decomposition to describe all modes in the spectral domain. The second describes the configuration of the circuit in the spatial domain. It allows taking the exact structure according to the appropriate boundary conditions. This method permits to reduce numerical complexity. The convergence of this approach is always guaranteed. The theoretical suggested study is validated by the simulation of two different examples of SIW circuits. The obtained results are in good agreement with those of measurement and with software HFSS simulations, which prove the advantage of this method.

A new formulation of the boundary condition at infinity for a hybrid radiation model is introduced. It is shown that its application leads to an iterative solution of the problem in the spectral domain. The validity of the condition is proved by its application to the analysis of a laterally shielded dielectric slab. Using this condition, an iterative method in the spectral domain is proposed in order to analyze striplike stratified transmission lines. As a result, two solutions, classified as perturbed longitudinal electric (LSE) and longitudinal section magnetic (LSM) modes, are obtained. Numerical results concerning the convergence of the method as well as the field distribution are presented for the case of a microstrip line.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>