A passive SPICE model for rectennas

Polyanna Mara Pereira (The Electrical Engineering Graduate Program, Federal University of Minas Gerais, Belo Horizonte, Brazil)
Felipe Campelo (Department of Electrical Engineering, Federal University of Minas Gerais, Belo Horizonte, Brazil)
Takuya Mori (Graduate School of Information Science and Technology, Hokkaido University, Sapporo, Japan)
Hajime Igarashi (Graduate School of Information Science and Technology, Hokkaido University, Sapporo, Japan)
Ricardo Adriano (Department of Electrical Engineering, Federal University of Minas Gerais, Belo Horizonte, Brazil)

Abstract

Purpose

This paper aims to present a SPICE model to represent antennas in receiving mode. The model can be used to evaluate the performance of the antenna when it is coupled to several different nonlinear electric circuits. The proposed methodology is particularly suitable for rectenna applications, as it allows the analysis of different configurations for a rectenna more efficiently than using full-wave analysis simulators coupled directly to each rectifier circuit.

Design/methodology/approach

The model presented uses reciprocity theory to calculate the ideal voltage source of the Thevenin-equivalent circuit for an antenna. Vector fitting is then used to approximate the model to rational functions that can be converted to Resistor, Inductor and Capacitor circuits. Additional components are added to the circuit to prevent numerical instability.

Findings

Two rectennas are used to illustrate the performance of the proposed model, one based on a 2.45-GHz rectangular patch antenna and another based on a planar spiral antenna. The second antenna has impedance with positive and negative real parts along the frequency range, which could lead to numerical instabilities. The proposed method is shown to be stable while working with these negative resistance values, which may appear during circuit parameterization.

Research limitations/implications

The equivalent SPICE circuit model for the antenna makes it easy to simulate nonlinear circuits connected to the antenna and perform transient analyses. The computational cost of antenna analysis is reduced, being more computationally efficient than methods that involve full-wave simulation. This characteristic makes it an interesting approach for working with rectennas, or any application where the time constant of the circuit is much longer than the period of the incident wave.

Originality/value

For most antenna applications, the numerical stability of the circuit can be achieved using passive enforcement. However, depending on the phase response of the antenna, the impedance that represents its far-field characteristic may present a negative real part, in which case, passive enforcement will fail. In this paper, the problem of numerical instability is solved by introducing an offset resistance and a current-controlled voltage source to the model.

Keywords

Acknowledgements

This paper forms part of a special section “Microwave Energy Applications (3GCMEA 2016) ”, guest edited by Juan Monzó-Cabrera.

This work was supported by the Brazilian funding agencies FAPEMIG, CNPq and CAPES; by the Japanese Society for the Progress of Science (JSPS); and by the Universidade Federal de Minas Gerais, Brazil, and Hokkaido University, Japan.

Citation

Pereira, P.M., Campelo, F., Mori, T., Igarashi, H. and Adriano, R. (2018), "A passive SPICE model for rectennas", COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, Vol. 37 No. 6, pp. 1905-1917. https://doi.org/10.1108/COMPEL-04-2017-0163

Download as .RIS

Publisher

:

Emerald Publishing Limited

Copyright © 2018, Emerald Publishing Limited

To read the full version of this content please select one of the options below

You may be able to access this content by logging in via Shibboleth, Open Athens or with your Emerald account.
To rent this content from Deepdyve, please click the button.
If you think you should have access to this content, click the button to contact our support team.