Dielectric resonator, dielectric notch filter, and dielectric filter

A dielectric notch filter comprising:

• a transmission line for transmitting a high-frequency signal;
• an input terminal and an output terminal provided at both ends of the transmission line;
• a ground conductor for supplying a ground potential;
• and
• a plurality of dielectric resonators connected to the ground conductor and the transmission line,
• wherein the dielectric notch filter further comprises a plurality of impedance matching means connected to the ground conductor and the transmission line in parallel with the plurality of dielectric resonators, and each of the dielectric resonators includes:
• a cavity connected to the ground conductor;
• a dielectric block provided in the cavity;
• a coupling device coupled with an electromagnetic field produced in the cavity;
• and
• a coupling adjusting line for connecting the coupling device to the transmission line and for adjusting the degree of electromagnetic coupling,
• resonance frequencies of the respective plurality of dielectric resonators being distributed symmetrically with respect to a filter center frequency.

A dielectric resonator comprising:

• a cavity;
• a dielectric block fixed in the cavity;
• and
• a coupling device coupled with an electromagnetic field produced in the cavity,
• wherein a through hole is formed in the dielectric block, a fixing shaft formed of a dielectric material is allowed to pass through the through hole, and one end of the fixing shaft is fixed to the cavity by a presser member.

A dielectric resonator comprising:

• a bolt formed of a dielectric material;
• a bolt pressing plate having a through hole;
• a supporting member having a through hole;
• a dielectric block having a through hole;
• and a cavity, wherein the bolt is allowed to pass through the through holes of the bolt pressing plate, the supporting member, and the dielectric block in this order, and fastened with a nut, thereby constituting a resonator unit, the resonator unit being fixed to the cavity.

A dielectric resonator comprising:

• a dielectric block having one of a columnar shape or a cylindrical shape and having a diameter d and a height h;
• and a rectangular parallelepiped metal cavity having a width W, a depth D, and a height H,
• wherein the dielectric block is held in a center portion of the metal cavity, and
• a ratio of the depth D to the diameter d is in the range of 1.3 to 2.0, a ratio of the width W to the diameter d is in the range of 2.0 to 4.0, and a ratio of the width W to the depth D is in the range of 1.2 to 2.5.

A dielectric filter comprising:

• N dielectric blocks each having one of a columnar shape or a cylindrical shape and having a diameter d and a height h, N being an integer of 2 or more;
• a single metal case having a rectangular parallelepiped shape and having a width W, a depth N×D, and a height H;
• and
• (N−1) metal partitions each having a width W and a height H,
• wherein the metal case is divided by the metal partitions into substantially equal portions along a direction of the depth N×D, thereby forming N rectangular parallelepiped cavities having the width W, a depth D, and the height H, and
• the dielectric blocks are held in the center portions of the cavities, respectively, a ratio of the depth D to the diameter d being in the range of 1.3 to 2.0, a ratio of the width W to the diameter d being in the range of 2.0 to 4.0, and a ratio of the width W to the depth D being in the range of 1.2 to 2.5.

A dielectric resonator comprising:

• a cavity having a first threaded hole;
• a dielectric block provided in the cavity;
• a coupling device coupled with an electromagnetic field produced in the cavity;
• a frequency tuning member having a screw portion which is spirally engaged with the first threaded hole of the cavity, a distance between the dielectric block and the frequency tuning member being changed by rotating the frequency tuning member, for tuning a resonance frequency of the cavity depending on the distance;
• fixing means for fixing a relative positional relationship between the frequency tuning member and the cavity,
• wherein the fixing means fixes the cavity and prevents the frequency tuning member from rotating due to a frictional force caused between the first threaded hole of the cavity and the screw portion of the frequency tuning member.