Wireless-Fed Pinching-Antenna Systems with Horn Antennas

TL;DR

This paper proposes a wireless-fed pinching-antenna system with horn antennas and a relay to extend coverage in high-frequency communications, optimizing power and antenna placement for improved efficiency.

Contribution

It introduces a novel relay-assisted architecture with joint optimization of antenna position, relay gain, and transmit power, achieving better power efficiency than existing systems.

Findings

Significant power savings compared to conventional systems.

Optimal antenna placement balances waveguide attenuation and free-space loss.

Closed-form solutions for relay gain and transmit power.

Abstract

Pinching-antenna systems have recently emerged as a promising solution for enhancing coverage in high-frequency wireless communications by guiding signals through dielectric waveguides and radiating them via position-adjustable antennas. However, their practical deployment is fundamentally constrained by waveguide attenuation and line-installation requirements, which limit the achievable coverage range. To address this challenge, this paper investigates a wireless-fed pinching-antenna architecture that employs highly directional horn antennas to enable efficient coverage extension. Specifically, a full-duplex amplify-and-forward relay equipped with horn antennas is introduced between the base station and the waveguide input, which significantly improves the link budget in high-frequency bands while effectively eliminating self-interference. On this basis, we formulate a total power minimization problem subject to a quality-of-service constraint at the user equipment, involving the joint optimization of the pinching-antenna position, the relay amplification gain, and the base station transmit power. By exploiting the structure of the end-to-end signal-to-noise ratio, the optimal pinching-antenna position is first obtained in closed form by balancing waveguide attenuation and free-space path loss. Subsequently, closed-form expressions for the optimal relay gain and transmit power are derived. Numerical results demonstrate that the proposed scheme substantially outperforms conventional systems without relaying and relay-assisted transmission with fixed antennas in terms of total power consumption.