Integrated air-filled waveguide antennas in LTCC for G-band operation

In this paper, a new concept in planar transmission lines is introduced, namely the air-filled substrate integrated waveguide. The air-filled guide was fabricated within an LTCC planar circuit. Measurements were made over G-band (140GHz-220GHz) which showed the integrated guide had insertion losses comparable, or slightly less, than other planar transmission lines at these frequencies. To further demonstrate the potential of the new structure a 150GHz slot antenna, using integrated air-filled waveguide, was designed and tested. The principal significance of the new integration technology proposed here is that it will permit the integration of air-filled, high-Q cavity filters and allow the closed integration of efficient slot antennas with front-end circuitry.