Wideband impedance network design of 3-D printed Vivaldi antenna based on surface wave suppression

Aiming at fast radio burst (FRB) observation and receiving other radio frequency signals in process of deep space exploration, an additive manufactured C- and X-band 3-dimensional (3-D) printed Vivaldi antenna element is designed for phased array feed in radio telescope applications in astronomy observatories. To realize the impedance match between coaxial feeding probe and the parallel waveguide transmission line connected with the exponential shaped radiation flares, a 3-D printed Marchand Balun for the Vivaldi antenna element is designed and optimized to help the Vivaldi antenna cover 4–12 GHz bandwidth. Benefited from additive manufacturing processing, a cylindrical cavity and an arch sector that are difficult to realize by traditional machining are loaded in the parallel plate waveguide (PPW) transmission line to suppress the surface wave. Therefore, the mismatch in both high and low part of the 4–12 GHz working band is offset and good stability of antenna gain in the required C- and X-band is maintained.