C-PASS: Center-Fed Pinching Antenna System

TL;DR

This paper introduces C-PASS, a novel center-fed pinching antenna system that doubles the degrees of freedom and enhances multiplexing gain, leading to significant capacity improvements over traditional end-fed PASS systems.

Contribution

The paper proposes a new center-fed antenna architecture and derives theoretical expressions showing its superior multiplexing capabilities compared to conventional systems.

Findings

C-PASS achieves twice the DoF of traditional PASS.

The system provides an additional multiplexing gain of (P_T   N^2) over conventional designs.

Numerical results confirm substantial capacity improvements with C-PASS.

Abstract

A novel architecture of the center-fed pinching antenna system (C-PASS) is proposed. In contrast to the conventional end-fed PASS, signals are fed from the center input ports and propagate towards both sides of the waveguide. By doing so, spatial-multiplexing gain can be achieved in a single waveguide. Based on the proposed C-PASS, closed-form expressions for the degree of freedom (DoF) and power scaling laws are derived. These theoretical results reveal that C-PASS can achieve \emph{twice} the DoF and an additional multiplexing gain of $\mathcal{O}(P_T \ln^4 N/N^2)$ compared to the conventional PASS, where $P_T$ and $N$ represent the transmit power and pinching antenna number, respectively. Numerical results are provided to demonstrate that substantial capacity improvements can be achieved through the enhanced DoF and multiplexing gain of the C-PASS.