Pencil-Beam Single-point-fed Dirac Leaky-Wave Antenna on a Transmission-Line Grid

TL;DR

This paper introduces a novel single-point-fed 2D Dirac leaky-wave antenna using a transmission-line grid, capable of generating pencil beams at various angles, supported by analytical design and experimental validation.

Contribution

It presents the first design of a 2D Dirac leaky-wave antenna on a transmission-line grid that produces pencil beams at broadside and tilted angles, with analytical and experimental validation.

Findings

The TL-grid unit cell exhibits a closed bandgap with linear frequency variation.

The antenna successfully generates pencil beams at broadside and tilted angles.

Experimental results confirm the theoretical design.

Abstract

Leaky-wave antennas (LWAs) are widely used as single-point-fed linear antenna arrays. The extension of LWAs to 2D implies that they can be used as single-point-fed 2D antenna arrays without requiring a complex feeding network. However, generating a pencil beam from 2D LWAs is not straightforward and due care has to be taken for the design of the LWA. On the other hand, transmission-line (TL) grids have demonstrated interesting behaviors, such as an effective negative refractive index and growing of evanescent waves. In this paper, a singlepoint-fed TL-grid 2D Dirac leaky-wave antenna (DLWA) design is proposed that generates a pencil beam at both broadside and slightly tilted angles. The TL-grid unit cell is analytically treated in light of its scattering and impedance matrices. The optimized TL-grid unit cell is shown to exhibit a closed bandgap in the dispersion relation which is also linearly varying with frequency (hence it is a DLWA). The proposed 2D DLWA design is fabricated and the experimental results are presented.