This document describes techniques, apparatuses, and systems for a multi-layer air waveguide with layer-to-layer connections. Each pre-formed layer of the air waveguide is attached to at least one other pre-formed layer by a mechanical interface. The mechanical interface may be a stud-based interface, a snap fastener-based interface, a ball-and-socket based interface, or a pressure contact interface utilizing irregular roughed surfaces of each pre-formed layer. The mechanical interfaces of the pre-formed layers structurally hold the air waveguide together and electrically couple all of the pre-formed layers. In this manner, the cost of manufacturing the air waveguide antennas may be less expensive than previous manufacturing processes.