Dielectric filter unit comprising three or more dielectric blocks and a transmission line for providing electromagnetically coupling among the dielectric resonators

A communication device comprising:

• a dielectric filter unit including
• three or more dielectric blocks including a first dielectric block and a second dielectric block, the three or more dielectric blocks being arranged adjacent to each other in a predetermined direction, and
• a transmission line,
• wherein the three or more dielectric blocks include a third dielectric block between the first dielectric block and the second dielectric block, the third dielectric block being different from the first dielectric block and the second dielectric block,
• each of the three or more dielectric blocks is electromagnetically coupled to one or two adjacent dielectric blocks included in the three or more dielectric blocks, and
• the first dielectric block and the second dielectric block are electromagnetically coupled to each other through the transmission line, and the transmission line is electromagnetically isolated from the third dielectric block or is electromagnetically coupled to the third dielectric block more weakly than is coupled to the first dielectric block and the second dielectric block.

A dielectric filter unit, comprising:

• three or more dielectric blocks including a first dielectric block and a second dielectric block, the three or more dielectric blocks being arranged adjacent to each other in a predetermined direction;
• and
• a transmission line,
• wherein the three or more dielectric blocks include at least one dielectric block between the first dielectric block and the second dielectric block,
• the three or more dielectric blocks each having closed end faces which are completely covered by a conductive layer,
• each of the three or more dielectric blocks is electromagnetically coupled to one or two adjacent dielectric blocks included in the three or more dielectric blocks, and
• the transmission line is electromagnetically coupled to the first dielectric block and the second dielectric block.

A communication device comprising:

• a dielectric filter unit including
• three or more dielectric blocks including a first dielectric block and a second dielectric block, the three or more dielectric blocks being arranged adjacent to each other in a predetermined direction, and
• a transmission line,
• wherein the three or more dielectric blocks include at least one dielectric block between the first dielectric block and the second dielectric block,
• the three or more dielectric blocks each having closed end faces which are completely covered by a conductive layer,
• each of the three or more dielectric blocks is electromagnetically coupled to one or two adjacent dielectric blocks included in the three or more dielectric blocks, and
• the transmission line is electromagnetically coupled to the first dielectric block and the second dielectric block.