Waveguide resonators in planar form for oscillator and filter applications

In this paper a new direct integration of rectangular waveguide with planar circuits on the same substrate is presented. Since the design of such structure is very complex, first the substrate integrated rectangular waveguide is converted to an equivalent rectangular waveguide, so that the well established rectangular waveguide design theory can be applied. Periodic resonator at 3.5 GHz and 28 GHz is designed, simulated, fabricated and tested. This resonator structure is then used for filter and oscillator applications. Bandpass filter and oscillator at 28 GHz are designed and simulated. The proposed technique shows promising features such as reduced size, reduced cost and more compact resonator and filter structures, while maintaining easy fabrication process.