Design of Broadband Double-Ridge Horn Antenna for Millimeter-Wave Applications

In this paper, a broadband double-ridge horn antenna (DRHA) covering 5G millimeter-wave (mm-wave) band is proposed, which maintains stable radiation pattern and gain in the entire band. By redesigning the transition between coaxial and waveguide, there is no splitting or deterioration in the axis pattern throughout the entire 18–54 GHz frequency band, and the VSWRs are all below 2. Meanwhile, by replacing the H-Side wall of the antenna with metal grid, the variation on 3 dB beamwidth of the radiation pattern also become more stable against frequencies. In order to fabricate the prototype successfully, the method of block processing and assembly is adopted, which can ensure high precision machining and make the assembly simple and easy to operate. Prototype measurement results show that the VSWR of the antenna is in well agreement with the simulation ones, while the gain is stable as well as no pattern splitting in the entire frequency band can be observed. It will find potential applications in 5G mm-wave frequency band, especially in the field of antenna measurement system as a standard calibration antenna or a probe antenna.