Advances in additive manufacturing technologies allow for the rapid, inexpensive manufacturing of microwave circuits. Circuits made using additive manufacturing are comparable in performance to circuits produced circuits produced using conventional methods such as printed circuit board fabrication, thin film deposition, machining, and milling. Very little work has been done in making additively manufactured transitions, specifically those going from a planar transmission line medium to a rectangular waveguide. This thesis presents a magnetically coupled aperture and patch microstrip to rectangular waveguide transition cascaded with a coplanar waveguide to microstrip feed, manufacturable using fused deposition modelling and microdispensing. It has rectangular waveguide flange bolt holes, which allows a rectangular waveguide to be securely attached. In simulation, at 15dB return loss, it has 0.8 GHz of bandwidth, centered at 10 GHz. It has a minimum insertion loss of 0.89 dB.