Non-Conformal Design and Fabrications of Single Arm Conical Log Spiral Antenna

For a conical log spiral antenna (CLSA), it is quite common to place the strip conductor conformally to the conical surface, and the antenna requires an extra impedance matching network. On the other hand, non-conformal orientation can solve the impedance matching issue, but fabrication is not as straightforward as conformal placement. This work considers the non-conformal placement of a strip conductor which facilitates self-matching while using smart additive manufacturing techniques for prototyping to ease the fabrication complexity. The impact of the additional dielectric support on the performance parameters of CLSA is investigated. Finally, the CLSA was prototyped using two different conductive elements (copper strip and conductive paint) on the 3D-printed support. Experimental and numerical results are shown to agree well for both copper strip and paint-based approaches. The self-matched CLSA provided a maximum impedance bandwidth of 128%, 3-dB axial ratio bandwidth (AR BW) of 63.56%, and gains of 10.32 +/- 1.94 dBi. The additive manufacturing techniques are shown to allow design flexibility and mitigate fabrication difficulties.