PURPOSE: To simplify the production process and to make a tri-plate structure type dielectric filter small-sized and thin by eliminating a need to work a dielectric substrate into stairs for the purpose of providing a slit for coupling.
CONSTITUTION: Quarter-wave resonator inner conductors 107a and 107b are provided on the lower face of an upper dielectric substrate 101 and the upper face of a lower dielectric substrate 102. Conductors 108 for coupling are provided on the lower face of the upper dielectric substrate 101 and the upper face of the lower dielectric substrate 102. Conductors 108 are provided up art from the side faces S by a prescribed distance (d) opposite to the face side faces S on open end sides of quarter-wave resonator inner conductors 107a and 107b and form parallel plane plate capacitors together with quarter-wave resonator inner conductors 107a and 107b respectively. The lower face of the upper dielectric substrate 101 and the upper face of the lower dielectric substrate 102 where quarter-wave resonator inner conductors 107a and 107b and conductors 108 for coupling are provided in this manner are stuck to each other to constitute the dielectric filter.
TESHIGAWARA OSAMU
IIJIMA HIROAKI
