Applying additive manufacturing to integrate coaxial connectors with 3D printed waveguides for cascaded RF link applications

This paper explores the use of additive manufacturing as a low-cost method to integrate coaxial SubMiniature version A (SMA) connectors with waveguides operating at X-band. The integration of coaxial connectors into the filter and waveguide designs via 3D printing eliminates the need for two additional bulky external SMA-to-waveguide transitions, and allows for customizable integrated SMA-to-waveguide transitions that minimize impedance mismatch. Four designs, including air-filled and polycarbonate (PC) dielectric-filled waveguides and two-pole filters, are modeled and manufactured using additive manufacturing to demonstrate this integrative approach. Placement of the coaxial connector in terms of depth and location is optimized in the designs for good match using simulation. PC dielectric posts are also incorporated into the device to provide additional reinforcement to the coaxial connectors without impacting the radio frequency (RF) performance. Good RF performance is achieved with the variation less than 0.39 dB between simulated and measured insertion loss results at the center of the device passband.