Generalized Scattering Matrix Formulation and its Relationship with TARC and Maximum Power Transfer Theorem

TL;DR

This paper introduces a comprehensive framework for analyzing passive multiport matching networks using a generalized Thevenin-Helmholtz model, connecting scattering matrices, TARC, and maximum power transfer principles.

Contribution

It develops a general impedance-based formulation for passive networks, linking TARC with the maximum power transfer theorem, applicable to complex interconnected systems.

Findings

Derived explicit scattering matrix for arbitrary passive networks

Established the connection between TARC and power conservation principles

Unified existing approaches into a broad, general framework

Abstract

In this paper, we present a rigorous framework for analyzing arbitrary passive matching networks using a generalized Thevenin-Helmholtz equivalent circuit. Unlike prior formulations, which often impose restrictive assumptions such as diagonal matching impedance matrices, our approach accommodates fully passive and interconnected multiport matching networks in their most general form. We first establish the mathematical conditions that any Linear Time Invarient, LTI, passive matching network must satisfy, starting from a $N \times N$ impedance matrix and continuing to $2N \times 2N$ and modified to follow the Thevenin-Helmholtz equivalent network. Using the Maximum Power Transfer Theorem (MPTT), we derive the scattering matrix $\mathbf{S}$ explicitly, showing its general applicability to arbitrary impedance configurations. Furthermore, we demonstrate the connection between the Total Active Reflection Coefficient (TARC) and the MPTT, proving that the TARC is inherently tied to the power conservation principle of the MPTT. This formulation not only unifies existing approaches, but also broadens the scope of applicability to encompass arbitrary physical passive systems. The equations and relationships derived provide a robust mathematical foundation for analyzing complex multiport systems, including interconnected phased arrays and passive antenna networks.