Design of a 3D Printed 4-Arm Conical Spiral Antenna

A four-arm conical spiral antenna is designed to operate in Mode 1 over a 2 to 8 GHz instantaneous bandwidth. The antenna has stable unidirectional radiation with high front-to-back ratio, axial ratio $< 2\mathbf{dB}$ within $\pm 30^{\circ}$ from the main beam, and radiation efficiency greater than 80%. Modifications to the metal-to-slot ratio are found to provide a simple means to control the impedance match. The final design includes a hollow conical shaped ground plane where receiver electronics can be integrated for a highly compact system.