A 3D-printed broadband millimeter wave absorber

TL;DR

This paper introduces a novel 3D-printed broadband millimeter wave absorber designed for CMB telescopes, demonstrating effective reflectivity over a wide frequency range and cryogenic durability.

Contribution

It presents a new additive manufacturing method for creating broadband millimeter wave absorbers with optimized design and verified performance.

Findings

Reflectivity measured from 63 GHz to 115 GHz and 140 GHz to 215 GHz.

Successfully survived cryogenic thermal cycling.

Manufactured using a space-filling curve design for manufacturability.

Abstract

We present the design, manufacturing technique, and characterization of a 3D-printed broadband graded index millimeter wave absorber. The absorber is additively manufactured using a fused filament fabrication (FFF) 3D printer out of a carbon-loaded high impact polystyrene (HIPS) filament and is designed using a space-filling curve to optimize manufacturability using said process. The absorber's reflectivity is measured from 63 GHz to 115 GHz and from 140 GHz to 215 GHz and is compared to electromagnetic simulations. The intended application is for terminating stray light in Cosmic Microwave Background (CMB) telescopes, and the absorber has been shown to survive cryogenic thermal cycling.