Dual-tapered microstrip-to-waveguide transition

A method of manufacturing an antenna assembly, the method comprising:

• fabricating a substrate, the substrate comprising:
• a first metal layer proximate to a first surface of the substrate;
• a second metal layer proximate to a second surface of the substrate opposite the first surface, wherein the second metal layer comprises a ground plane;
• a dielectric layer disposed between the first and second metal layers;
• and
• a microstrip-to-waveguide transition comprising:
• a microstrip feedline disposed at the first metal layer and extending along a centerline between a first terminal point and a second terminal point, the microstrip feedline comprising a microstrip element and a probe element;
• the microstrip element comprising:
• a connection segment to provide a circuit connection point, the connection segment extending from the first terminal point to a second point relative to the centerline and having a first width;
• a taper segment extending from the second point to a third point relative to the centerline, the taper segment tapering from the first width at the first point to a second width at the second point, the second width greater than the first width;
• and
• a first continuous-width segment extending from the third point to a fourth point relative to the centerline, the continuous-width segment having the second width;
• and
• the probe element extending from the fourth point to the second terminal point, the probe element having a third width at the fourth point, the third width less than the second width;
• a first waveguide opening comprising a first region extending from the fourth point and surrounding the probe element, the first region being substantially devoid of conductive material;
• and
• a plurality of metal vias disposed at the perimeter of the first waveguide opening and extending from the first metal layer to the second metal layer.

A method of operating an antenna assembly, the method comprising:

• providing a substrate comprising:
• a first metal layer proximate to a first surface of the substrate;
• a second metal layer proximate to a second surface of the substrate opposite the first surface, wherein the second metal layer comprises a ground plane;
• a dielectric layer disposed between the first and second metal layers;
• and
• a microstrip-to-waveguide transition comprising:
• a microstrip feedline disposed at the first metal layer and extending along a centerline between a first terminal point and a second terminal point, the microstrip feedline comprising a microstrip element and a probe element;
• the microstrip element comprising:
• a connection segment to provide a circuit connection point, the connection segment extending from the first terminal point to a second point relative to the centerline and having a first width;
• a taper segment extending from the second point to a third point relative to the centerline, the taper segment tapering from the first width at the first point to a second width at the second point, the second width greater than the first width;
• and
• a first continuous-width segment extending from the third point to a fourth point relative to the centerline, the continuous-width segment having the second width;
• and
• the probe element extending from the fourth point to the second terminal point, the probe element having a third width at the fourth point, the third width less than the second width;
• a first waveguide opening comprising a first region extending from the fourth point and surrounding the probe element, the first region being substantially devoid of conductive material;
• and
• a plurality of metal vias disposed at the perimeter of the first waveguide opening and extending from the first metal layer to the second metal layer;
• and
• communicating electromagnetic signaling via the microstrip feedline.