Integrated Carbon Fiber Microwave Circuits for Lightweight Antenna Applications

The implementation of a slotted substrate integrated waveguide (SIW) antenna within a fiber reinforced composite is presented as a lightweight method of integrating microwave functionality into composite components. The SIW circuit is fabricated within a foam core composite using copper-coated carbon veils. The use of a coated veil as the conductor reduces the attenuation effects normally experienced with carbon-based microwave circuits, while minimizing the introduction of additional materials that could mechanically weaken the composite. The application of an integrated composite SIW as an antenna is demonstrated through the design, fabrication and gain characterization of two slotted waveguide antennas, with measured gains of -3 dBi at 3.66 GHz and 0.2 dBi at 6.75 GHz respectively.