arXiv subjects

Renzun Lian

Publications and source records attributed to Renzun Lian.

5 recordsLinked to original sources

arXiv2021

Research on the Power Transport Theorem Based Decoupling Mode Theory for Transceiving Systems

The physical pictures of eigen-mode theory (EMT) and the conventional characteristic mode theory (CMT) reveal a fact that: the EMT and CMT are the modal theories for electromagnetic wave-guiding and scattering (for details, please see the Appendices E, F, G and H) systems respectively, rather than for electromagnetic transceiving systems. This Postdoctoral Research Report is devoted to establishing a novel modal theory - decoupling mode theory (DMT) - for transceiving systems, and constructing the energy-decoupled modes (DMs) of objective transceiving system. This Postdoctoral Research Report is a companion volume of the author's Doctoral Dissertation "Research on the Work-Energy Principle Based Characteristic Mode Theory for Scattering Systems" (arXiv:1907.11787).

eess.SP↗

arXiv2019

Research on the Work-Energy Principle Based Characteristic Mode Theory for Scattering Systems

Electromagnetic (EM) scattering systems widely exist in EM engineering domain. For a certain objective scattering system, all of its working modes constitute a linear space, i.e. modal space. Characteristic mode theory (CMT) can effectively construct a basis of the space, i.e. characteristic modes (CMs), and the CMs only depend on the inherent physical properties of the objective system, such as the topological structure and the material parameter of the objective system. Thus, CMT is very valuable for analyzing and designing the inherent EM scattering characters of the objective system. This work finds out that integral equation (IE) is not the best framework for carrying CMT. This dissertation proposes a completely new framework for carrying CMT, i.e. work-energy principle (WEP) framework, and at the same time proposes a completely new method for constructing CMs, i.e. orthogonalizing driving power operator (DPO) method. In new WEP framework and based on new orthogonalizing DPO method, this work resolves 5 pairs of important unsolved problems existing in CMT domain.

physics.class-ph↗

arXiv2018

On Huygens' Principle, Extinction Theorem, and Equivalence Principle (Inhomogeneous Anisotropic Material System in Inhomogeneous Anisotropic Environment)

Huygens' principle (HP), extinction theorem (ET), and Franz's / Franz-Harrington formulation (FHF, which is a mathematical expression of surface equivalence principle) are the important components of electromagnetic (EM) theory, and they are generalized from the following aspects. 1) Traditional HP, ET, and FHF in homogeneous isotropic environment are generalized to inhomogeneous anisotropic lossy environment. 2) Traditional FHF for homogeneous isotropic material system is generalized to inhomogeneous anisotropic lossy material system in this paper, and will be further generalized to metal-material combined system in future works. 3) The Huygens' surface in traditional HP and ET is a single closed surface. In this paper, it is generalized to the "Huygens' surface" which is constructed by multiple closed surfaces. In future works, it will be further generalized to the "Huygens' boundary" which includes some lines and open surfaces. 4) For a material body, traditional FHF has only ability to express the external scattering field and the internal total field (the summation of scattering and incident fields) in terms of the equivalent sources on material boundary, and it is generalized to formulating the internal scattering and incident fields in this paper. In addition, the relationships among HP, ET, and FHF are studied, and it is proved that HP and ET are equivalent to each other.

physics.class-ph↗

arXiv2018

On Huygens' Principle, Extinction Theorem, and Equivalence Principle (Metal-Material Combined System in Inhomogeneous Anisotropic Environment)

In this paper, we generalize Huygens' principle (HP), extinction theorem (ET), and Franz-Harrington formulation (FHF). In our previous works, the traditional HP, ET, and FHF in homogeneous isotropic environment are generalized to inhomogeneous anisotropic lossy environment; the traditional FHF of homogeneous isotropic material system is generalized to inhomogeneous anisotropic lossy material system and then to piecewise inhomogeneous anisotropic lossy material system; the traditional HP, ET, and FHF of simply connected material system are generalized to multiply connected system and then to non-connected system; the traditional FHF of external scattering field and internal total field are generalized to internal scattering field and internal incident field. In previous work, it is proved that the generalized HP (GHP) and generalized ET (GET) are equivalent to each other; the GHP, GET, and generalized FHF (GFHF) satisfy so-called topological additivity, i.e., the GHP/GET/GFHF of whole electromagnetic (EM) system equals to the superposition of the GHP/GET/GFHF corresponding to all sub-systems. In this paper, the above results obtained in our previous works, which focuses on the EM system constructed by material bodies, are further generalized to the metal-material combined EM system in inhomogeneous anisotropic lossy environment, and traditional surface equivalence principle is generalized to line-surface equivalence principle.

physics.class-ph↗

arXiv2016

Electromagnetic-Power-based Characteristic Mode Theory for Perfect Electric Conductors

In this paper, an ElectroMagnetic-Power-based Characteristic Mode Theory (CMT) for PEC systems (PEC-EMP-CMT) is built. The PEC-EMP-CMT is valid for the PEC systems which are surrounded by any electromagnetic environment, and it can construct the complex characteristic currents and non-radiative Characteristic Modes (CMs). In this paper, some traditional concepts, such as the system input impedance and modal input impedance etc., are redefined; the traditional characteristic quantity, Modal Significance (MS), is generalized; a series of new power-based CM sets are introduced. It is proven in this paper that various power-based CM sets of a certain objective PEC structure are independent of the external environment and excitation; the non-radiative space constituted by all non-radiative modes is identical to the interior resonance space constituted by all interior resonant modes of closed PEC structures, and the non-radiative CMs constitute a basis of the space. Based on above these, the normal Eigen-Mode Theory (EMT) for closed PEC structures is classified into the PEC-EMP-CMT framework. In addition, a variational formulation for the external scattering problem of PEC structures is provided in this paper, based on the conservation law of energy.

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