3D MUX - 3D printed multiplexer for wireless communications

Waveguide transmission lines and components have been traditionally made using bulk metals, requiring an expensive fabrication process and resulting in heavy circuits. In this project the production of a lightweight prototype made using 3D printing and electroless plating is proposed (weight reduction will be dramatically obtained by replacing machined metal pieces for 3D printed metal coated resins). The multiplexer design is based on coupled resonators (this approach can reduce the size of conventional multiplexers estimated in the order of 20% or more, adding filtering properties to the design), where a coupling matrix defines the overall response of the device, resulting in a very flexible design implementation that can be tailored to customers’ needs by creating the coupling matrix according to customer’s specification. The design can then be 3D printed and plated to complete the production process.

The key difference between the proposed multiplexer made of only resonators and a filter is the introduction of the ‘junction resonator’. It is dual-functional and used not only to form a resonant pole but also to split the signal as is normally done by a transmission-line junction. This has provided significant benefits to microwave circuit designs. By replacing transmission lines with resonators, the proposed multiplexer implementation enables embedded filtering function in traditional non-filtering circuits.