Nested Horn-Based 3D-Printed Dual-Band High-Gain Conical Beam Antenna

Abstract

Dual-band antennas have found extensive applications in the fields of communications, guidance, tracking systems, etc. However, traditional designs often struggle to simultaneously achieve high gain, wide impedance bandwidth and conical beam characteristics. In response to this challenge, a dual-band high-gain conical beam antenna with broad impedance bandwidth based on a nested horn operating at Ku-/Ka-band is presented in this paper. The nested horn excited by metal probes comprises a Ka-band circular waveguide horn and an outer nested Ku-band waveguide horn. The proposed antenna operates in the TM₀₁ mode, demonstrating rotationally symmetrical field distribution, which enables the generation of conical beams. The utilisation of a ridge waveguide further widens the impedance bandwidth. The incorporation of dual reflectors enhances the directivity of electromagnetic wave propagation, leading to increased gain and a fixed beam pointing angle. The measured results show that the proposed antenna operates at 12.8–18 GHz in the Ku-band and 25.2–43.5 GHz in the Ka-band, with relative impedance bandwidths of approximately 33.8% and 53.3%, respectively, covering nearly the entire Ku-band and Ka-band. The peak gain reaches 12.2 dBi at 15 GHz and 16.4 dBi at 40 GHz. Furthermore, the maximum beam pointing angles are maintained at 30° for both frequency bands.