3D Printing of Double Ka Band Helical Antenna

A.-M. Lanouette, J. Hill, P.D. Dussault, J.-J. Laurin, D. Therriault
École Polytechnique de Montréal, CA

Keywords: helical antenna, direct-write, ka band, thermoplastic, fast-drying ink


We present a rapid and low-cost fabrication technique to build a small array of antennas operating in the Ka band (20-30GHz). The designed antenna prototypes have a wire diameter of 0.2mm, a helix diameter of 3.4mm, a total height of 23.2mm and 8 turns as shown in Fig. 1. These helical antennas also feature a variable pitch for double band functionality, allowing them to both receive and transmit a signal in different frequency ranges (uplink: 30.0 to 31.0GHz, downlink: 20.2 to 21.2GHz). The fabrication method proposed here is a combination of the three-dimensional (3D) direct-write printing of a thermoplastic template followed by its metallic coating using an electrochemical method. The 3D printing consists of the robotic deposition of an ink material extruded through a micronozzle under constant pressure. The ink material was a fast-drying thermoplastic solution composed of dichloromethane (DCM) and ~30wt% of polylactic acid (PLA). The PLA helices were later released from the mandrel and coated by a ~50μm copper layer using sputtering and an electrolytic bath. Our manufacturing approach show high potential to rapidly and cheaply build high-frequency compact antennas which could lead to new opportunities for modern satellites, ground and mobile communication stations.