Three‐dimensional‐printed strip and paint‐based semiellipsoidal helical antenna

Abstract

A semiellipsoidal helical antenna (SEHA) is formed by scaling a hemispherical antenna in the axial direction. Effects of scaling factors on reflection coefficient (S11), axial ratio bandwidth (AR BW), and gains were analyzed thoroughly. By considering the best scaling factor, analysis is continued for strip‐based SEHA. It is observed that keeping the strip face parallel to the ground plane eliminates the concern of extra impedance matching issues and improves the overall performance over its wire‐based counterpart. For prototyping, the antenna is constructed independently on polylactic acid and acrylonitrile butadiene styrene plastic‐based supportive structures. Simulated and measured results are well agreed upon. When the height (h) in the axial direction is twice the hemispherical radius (r), the antenna provided maximum impedance and 3‐dB AR bandwidths of 144% and 77.53%, respectively, with a maximum gain of 8.83 dBi. The proposed antenna would be a good contestant in satellite communication where a broadband circularly polarized antenna is required.

Fabrications of electrically small hemispherical antenna

“…Works have also been done to fabricate complexshaped helix antennas using 3D printing and conductive paint. [14][15][16] In this work, the ESA design is scaled up at a frequency of 1.85 GHz for assessing the applicability of additive manufacturing in small and complex-shaped structure. Moreover, conductive strip-based folded ESA with constant strip widths, and conformal placement is new compared with its wire counterpart which provided more flexibility of choosing conductor materials.…”

“…A rapid prototype of a wire‐type ESA was fabricated by Kim et al 13 The author used a successive polycrystalline copper coating on a 3D‐printed dielectric structure using a selective laser sintering (SLS) technique. Works have also been done to fabricate complex‐shaped helix antennas using 3D printing and conductive paint 14–16 …”