Waveguide-microstrip transmission line transition structure having an integral slot and antenna coupling arrangement

摘要

A waveguide-microstrip transmission line transition structure is provided having a microstrip transmission line structure adapted for coupling to an open end of a waveguide. The microstrip transmission line structure includes a microstrip transmission line having a ground plane conductor and an antenna electrically coupled to the microstrip transmission line through an aperture in the ground plane conductor. The ground plane conductor is adapted for mounting in a plane intersecting a longitudinal axis of the waveguide. The antenna provides impedance matching between the microstrip transmission line and the waveguide. With such an arrangement, a relatively simpler manufacturable structure is provided because it is adapted for mounting to a standard waveguide flange and does not require specially machined waveguide pieces. The arrangement also provides modularity, in that the waveguide can be easily connected to and disconnected from the microstrip transmission line structure. Still further, the transition section does not require any special openings in the waveguide, thus eliminating spurious radiation and providing hermiticity. The structure is particularly well- suited for connecting planar antennas to waveguide feeds.