Ceramic dielectric band-pass filter comprising plural resonant cavities configured to form a sixth-order band-pass filter coupled to notch filters

A ceramic dielectric band-pass filter, comprising:

• a ceramic base;
• a first input and output electrode;
• and
• a second input and output electrode;
• wherein the ceramic base comprises an open surface, a short-circuit surface, and an input-output (IO) surface connected with the open surface and the short-circuit surface;
• the ceramic base comprises six first resonant cavities and two second resonant cavities;
• the six first resonant cavities and the two second resonant cavities penetrate the ceramic base from the open surface to the short-circuit surface;
• the six first resonant cavities and the two second resonant cavities are arranged along a length direction of the ceramic base;
• the six first resonant cavities are arranged between the two second resonant cavities;
• wherein the first input and output electrode and the second input and output electrode are arranged on the IO surface of the ceramic base and are spaced apart from each other and extend to the open surface of the ceramic base;
• the first input and output electrode, the second input and output electrode, and the six first resonant cavities are coupled to form a sixth-order band-pass filter;
• the first input and output electrode and one of the two second resonant cavities are coupled to each other to form one notch filter, and the second input and output electrode and the other one of the two second resonant cavities are coupled to each other to form another notch filter;
• a position of each of the two second resonant cavities is lower than a position of each of the six first resonant cavities;
• a diameter of each of the two second resonant cavities is variable in a direction from the open surface to the short-circuit surface;
• wherein the six first resonant cavities are through holes;
• a diameter of each of the six first resonant cavities ranges from 0.3-1 mm.

A ceramic dielectric band-pass filter, comprising:

• a ceramic base;
• a first input and output electrode;
• and
• a second input and output electrode;
• wherein the ceramic base comprises an open surface, a short-circuit surface, and an input-output (IO) surface connected with the open surface and the short-circuit surface;
• the ceramic base comprises six first resonant cavities and two second resonant cavities;
• the six first resonant cavities and the two second resonant cavities penetrate the ceramic base from the open surface to the short-circuit surface;
• the six first resonant cavities and the two second resonant cavities are arranged along a length direction of the ceramic base;
• the six first resonant cavities are arranged between the two second resonant cavities;
• wherein the first input and output electrode and the second input and output electrode are arranged on the IO surface of the ceramic base and are spaced apart from each other and extend to the open surface of the ceramic base;
• the first input and output electrode, the second input and output electrode, and the six first resonant cavities are coupled to form a sixth-order band-pass filter;
• the first input and output electrode and one of the two second resonant cavities are coupled to each other to form one notch filter, and the second input and output electrode and the other one of the two second resonant cavities are coupled to each other to form another notch filter;
• a position of each of the two second resonant cavities is lower than a position of each of the six first resonant cavities;
• a diameter of each of the two second resonant cavities is variable in a direction from the open surface to the short-circuit surface;
• wherein inner walls of the six first resonant cavities and inner walls of the two second resonant cavities are each coated with metal;
• one end of each of the six first resonant cavities located at the short-circuit surface of the ceramic base and one end of each of the two second resonant cavities located at the short-circuit surface of the ceramic base are coated with the metal;
• a thickness of the metal ranges from 4˜20 um.