Waveguide-to-Microstrip Antipodal End-Fire Antenna Design for mm-Wave Applications

This work introduces a practical, cost-effective solution for connecting an end-fire antenna working at mm-wave frequency using an ultra-low-cost FR4 substrate and WR-28 waveguide. The design is finalized in three steps, starting from WR-28 to microstrip, followed by Antipodal antenna analysis, and lastly, WR-28 to antipodal transition. The waveguide is designed to be realized using Direct Metal Laser Sintering (DMLS) technology, a metal 3D printing method, to create precise and budget-friendly waveguide structures. The transition is firstly tested using a microstrip line followed by an antipodal end-fire antenna that offers wide bandwidth and consistent radiation patterns across the mm-wave frequency range. Combining the affordability of FR4 substrates with the precision of DMLS technology; this work highlights a promising path toward developing high-performance, accessible solutions for the growing demands of mm-wave applications. The antenna tackles key challenges of this spectrum, including efficient power transfer, compact design, and durability, making it an excellent fit for nextgeneration mm-wave wireless communication systems.