Radiofrequency Antennas and Transmission Structures on Printed Photopolymers: Dielectric Loss, Metallisation and Geometry

Additively manufactured photopolymer substrates can carry radiofrequency antennas, resonators and transmission structures only when electromagnetic design is tied to the realised dielectric, metallisation and geometry. A nominal resin name does not establish relative permittivity, loss tangent or their frequency, temperature and moisture dependence; a nominal copper or metal coating does not establish sheet resistance, adhesion, thickness uniformity or continuity across edges; and a CAD trace width does not establish the effective conductor geometry after printing and finishing. Direct studies of SLA antenna substrates and metallised SLA reflectors demonstrate feasibility, while also showing that conductivity and fabrication state are process-dependent. This review develops a state-based qualification architecture for RF structures on printed photopolymers. It separates dielectric characterisation from conductor qualification, requires geometry and surface state to be measured at the frequencies and environmental states relevant to use, and links coupon measurements to device-level scattering parameters, radiation pattern and efficiency. The central conclusion is that electromagnetic performance belongs to the coupled material-metallisation-geometry-assembly state. Transfer between resin, printer, post-cure, coating route or frequency band requires evidence rather than nominal similarity.

ER-269 · Version 0.4.