A millimeter-wave transition from microstrip to waveguide using a Differential Microstrip Antenna

This paper presents a millimeter-wave transition from a Differential Microstrip Line (DMSL) to a rectangular waveguide. The key component of the transition is a Differential Microstrip Antenna (DMSA) - either a single patch DMSA or a gap-coupled patch DMSA. The gap-coupled patch increases significantly the bandwidth of the transition. Prototypes of both transitions were designed and manufactured, subsequent measurement results are in close agreement with the simulation results. This type of transition provides compact size and simple fabrication. It can be employed in a number of millimeter-wave applications.