High gain microstrip fed slot coupled hybrid antenna for MMW applications

A compact size enhanced gain hybrid antenna for millimeter wave (MMW) applications is investigated. The design adopts microstrip / circular waveguide hybrid technology for increasing the overall antenna gain to about 10 dB. Compared to the conventional circular patch antenna, the overall gain of the hybrid design increases by more than 3 dB over the entire operating range from 28 to 32 GHz, which makes it suitable for MMW imaging applications or in high bit rate short range communications. A slot feeding mechanism is used for exciting the microstrip patch dominant mode TM₀₁₀ which excites a circular waveguide TE₁₁ mode. The antenna prototype fabrication results show a very good agreement with the simulation results.