Novel cylindrical high-Q LTCC resonators for millimeter wave applications

This paper proposes cylindrical low temperature cofired ceramic (LTCC) resonator configurations as a means of achieving high-Q values at millimetric frequencies in a reduced-size structure. Cylindrical resonator geometries with via walls are compared with rectangular structures, showing a nearly 50% saving in circuit area. A design strategy for obtaining high-Q factors using appropriate loss-reduction and feeding techniques is described. A novel high-Q cylindrical resonator implementation is then carried out, yielding an unloaded Q of 840 at K-band, which is among the highest values ever reported using a standard LTCC process. Excellent agreement was obtained between EM modeling and measurements.