Printed tapered leaky-wave antennas for W-band frequencies

TL;DR

This paper presents the design, fabrication, and experimental validation of printed tapered leaky-wave antennas operating at 80 GHz, demonstrating effective side lobe suppression and reduced spurious radiation for W-band applications.

Contribution

It introduces a novel coarse discretization approach for printed leaky-wave antennas at mm-wave frequencies, enabling feasible fabrication and improved radiation control.

Findings

Side lobes suppressed to -18 dB

Effective control of spurious radiation

Validated through comprehensive near-field and far-field measurements

Abstract

Despite their great potential in communication and sensing applications, printed leaky-wave antennas have rarely been reported at mm-wave frequencies. In this paper, tapered leaky-wave antennas operating at 80 GHz are designed, fabricated and experimentally characterized. While most continuous leaky-wave antennas use subwavelength strips or other comparably small elements, in this work, the surface impedance is discretized very coarsely using only three square patches per period. With this architecture, a wide range of surface reactance can be achieved while maintaining a minimum feature size of the metallic pattern that is feasible for printed circuit fabrication. As the analytical solution for the bandstructure of sinusoidally modulated reactance surfaces is inaccurate for coarse discretization, we find it using full-wave simulation. In order to control side lobes effectively, we use a tapered aperture illumination according to the Taylor one-parameter distribution. A comprehensive experimental demonstration is presented, including near-field and far-field measurements. Therewith, we verify the designed aperture illumination and we reveal the origin of spurious far-field features. Side lobes are effectively suppressed and spurious radiation is reduced to -18 dB compared to the main lobe.