«QUADRUPOLE» MODE DR FILTER FOR C-BAND APPLICATIONS

The possibility of reducing the radiation loss of dielectric resonator (DR) to the external environment has been investigated for the first time by applying higher order mode of DR, namely “quadrupole” type, with higher Q factor. The “quadrupole” mode for constructing narrow band-pass filter (<1%) has been studied. The resonant frequencies of dielectric resonator have been calculated on grounds of approximate analytical method as well as finite element method. The coupling coefficients of the rectangular DR with coplanar line have been scrutinized both as a function of the glass substrate’s height, namely bs, on which the DR is situated, and as a function of the DR’s displacement toward the center line, namely y0. The synthesized two-resonator band-pass filter has the improved gain slope. The minimum value of insertion loss at the central frequency of 5.9 GHz is - 2.4dB, the shape factor is equal to 3.45