Small low Earth orbit (LEO) spacecraft are steadily improving their performance due to advanced \(21^{\textrm{st}}\) century hardware production methods. Additive manufacturing (AM), otherwise known as 3D printing, is contributing to the accelerated development of critical space hardware, including telemetry, tracking, and command (TT&C) equipment such as antennas. With this technology, structures can be built cost-efficiently using a single device, reducing extensive post-processing while offering increased design freedom for near-net-shaped parts. This study reveals an S-band rectangular dielectric resonator antenna (rDRA) operating at a resonant frequency of 2.54 GHz that can be integrated into a 1U cubesat footprint. The antenna is built using a conductive \(\hbox {TiO}_{2}\) -based composite dielectric filament shaped with a filament extrusion 3D printing process. The radio frequency (RF) properties of the feedstock are characterized to design the rDRA, becoming inputs to build and test the functional prototype. Validation results with over-the-air measurements are provided, with the rDRA exhibiting a gain, a fractional bandwidth, and a beamwidth of 6.7 dBi, 18.84%, and 82.3 \(^{\circ }\) , respectively. This work unlocks the potential to develop very simple and cost-effective S-band antennas for use in small satellites that can compete with their commercial counterparts, further offering new paths to manufacture antennas in situ, in space.
