Modeling of mutual coupling of arbitrary order in coupled circuits and array antennas

Abstract

This article presents a fundamental strategy for accurately modeling the mutual coupling of arbitrary order in any large-scale electromagnetic structures and high-density integrated chips such as antenna array elements and coupled circuit elements. The proposed method starts from the modeling of the first-order mutual coupling, and it consists of two main steps. First of all, an equivalent circuit model describing low-order mutual coupling (adjacent coupling) is characterized and established, of which each parametric value is accurately extracted by making use of a numerical calibration technique. Then, the circuit model for high-order mutual coupling (crossover or crosstalk coupling) is generated from the lower order models, and it can further be used for the modeling of mutual coupling of any higher order. The accuracy and efficiency of the proposed method are demonstrated by three different kinds of structure including a linear phased array antenna, a finite periodic electromagnetic structure, and a planar low-pass filter. This novel approach represents an easy, fast, and effective characterization of arbitrary-order mutual coupling. It can find applications in the modeling of mutual coupling between any circuit elements and building blocks such as antennas, resonators, and even small discontinuities, and it promises to be helpful for the analysis and iterative design of microwave circuits and antenna arrays.

An optimal far field radiation pattern synthesis of mutually coupled antenna arrays

“…The mutual currents may be calculated from the mutual impedance matrix by employing the concept of a twoport network as given in ( 4) and (5).…”

“…3,4 The performance of the antenna array degrades severely due to the presence of mutual coupling among the array elements, which causes an impedance mismatch, deviation of the radiation pattern, distortion and so forth. 2,5 A significant number of research works have been reported for the optimal radiation pattern synthesis of the concentric circular antenna array (CCAA), [6][7][8][9][10][11] where mutual coupling effect is not considered for the design purpose; hence, those results are not practically suitable. However, in this article, authors have employed the method of parametric assimilation technique (PAT) 12 for the correction of mutual coupling affected erred radiation pattern to the desired radiation pattern by using evolutionary optimisation techniques.…”

“…Nowadays, most research articles mainly focus on the mutual impedance for mutual coupling reduction and compensation. 5,[23][24][25][26] In this article, the mutual coupling effect of the DDE array and CCAA radiation pattern is corrected by using the PAT, which performs the matching and assimilation on the parameters like current amplitude excitation weights and inter-element spacing. To establish the method of PAT 16-elements DDE array of monopole antennas and (4,6,8), (8,10,12) elements CCAA of dipole elements with the presence of a central element (CE) are considered in this article.…”

“…For the practical design aspect, the minimisation of the physical size of the antenna array is desirable, leading to an increase in the mutual coupling effect among the array elements 3,4 . The performance of the antenna array degrades severely due to the presence of mutual coupling among the array elements, which causes an impedance mismatch, deviation of the radiation pattern, distortion and so forth 2,5 . A significant number of research works have been reported for the optimal radiation pattern synthesis of the concentric circular antenna array (CCAA), 6–11 where mutual coupling effect is not considered for the design purpose; hence, those results are not practically suitable.…”

“…Nowadays, most research articles mainly focus on the mutual impedance for mutual coupling reduction and compensation 5,23–26 . In this article, the mutual coupling effect of the DDE array and CCAA radiation pattern is corrected by using the PAT, which performs the matching and assimilation on the parameters like current amplitude excitation weights and inter‐element spacing.…”