Comparison of Additively Manufactured and Machined Antenna Array Performance at Ka-Band

Henri Kahkonen,Sebastian Proper,Ville Viikari,Juha Ala-Laurinaho

doi:10.1109/lawp.2021.3113372

Abstract

Additive manufacturing (AM) is a rapidly developing field, which potentially decreases the manufacturing costs and enables increasingly complex antenna shapes. Metal-based AM might be particularly useful for manufacturing antennas at millimeter-wave (mm-wave) range, because these antennas are physically small enough making AM cost efficient, and manufacturing accuracy could still suffice for good electrical performance. In this letter, two additively manufactured and identical machined fully metallic <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$Ka$</tex-math></inline-formula> -band Vivaldi antenna arrays are compared. The manufactured antenna arrays are compared using RF measurements to conclude the feasibility of AM for manufacturing antenna arrays at mm-wave frequencies. Comparison of the measured radiation patterns and realized gains of each of the antenna arrays between 26 and 40 GHz shows close to identical radiation patterns for all the arrays. A loss in realized gain of 0.5–1.5 dB is observed in the AM arrays when compared to the machined array due to the used materials and the surface roughness.

Highlights

V IVALDI antenna elements are very attractive for antenna arrays due to their performance
These antenna arrays can be manufactured with a few different manufacturing methods, for example, manufacturing the antenna array from a single piece of metal using wire electric discharge machining (WEDM), manufacturing the array from multiple separate parts using conventional machining methods, or on a PCBs arranged in a grid pattern
We extend the research on the Vivaldi antenna array design presented in [5], [12] by demonstrating the use of Additive manufacturing (AM) processes, namely, selective laser melting (SLM) and binder jetting to manufacture the fully metallic antenna array

Summary

Introduction

V IVALDI antenna elements are very attractive for antenna arrays due to their performance. Promising methods for producing metallic antenna arrays are metallizing additively manufactured plastic parts and direct metal printing, such as, selective laser melting (SLM) or binder jetting [6]–[11]. We extend the research on the Vivaldi antenna array design presented in [5], [12] by demonstrating the use of AM processes, namely, SLM and binder jetting to manufacture the fully metallic antenna array.

Results

Conclusion