PDF) Comparing Electrically Small Folded Conical and Spherical Helix Antennas Based on a Genetic Algorithm Optimization
Investigation of surface wave propagation along a folded cylindrical helix array
Folded conical helix antenna
Helical antenna - Wikipedia
Electrically small folded spherical helix antennas using copper strips and 3D printing technology - Kong - 2016 - Electronics Letters - Wiley Online Library
Figure 1 from Electrically-small folded cylindrical helix antenna for Wireless Body Area Networks | Semantic Scholar