Ceramic bandstop filter

Abstract

An embodiment of a unique ceramic bandstop filter is comprised of a dielectric plate having an input electrode disposed centrally on the top surface thereof and a dielectric block fixedly attached to the bottom surface of the plate and having a hole opposite the input electrode. The dielectric material is preferably a ceramic comprised of BaO, TiO 2 and ZrO 2 : The dielectric block is entirely plated with copper or silver except for a portion of the top surface surrounding the hole and is essentially a short-circuited coaxial transmission line. In another embodiment of the unique ceramic bandstop filter, a dielectric block has a hole extending between top and bottom surfaces thereof and an input electrode plated on the top surface near the hole. The dielectric block is entirely plated with copper or silver except for a portion of the top surface surrounding the input electrode and hole. Shunt capacitors or inductors can be plated on the top surface of both embodiments of the unique ceramic bandstop filter fr providing a bandstop/bandpass response characteristic.

We claim: 
     
       1. A bandstop filter comprising: first means comprised of a dielectric material and having top and bottom surfaces, said first dielectric means further including electrode means comprised of a conductive material disposed on the top surface;   second means comprised of a dielectric material and having top and bottom surfaces, said second dielectric means further including a hole extending from the top surface to the bottom surface thereof, and said second dielectric means further being covered entirely with a conductive material with the exception of the top surface; and   means for attaching the bottom surface of the first dielectric means to the top surface of the second dielectric means so that the electrode means on the top surface of the first dielectric means is arranged substantially opposite to the hole in the second dielectric means.   
     
     
       2. The bandstop filter according to claim 1, wherein the first dielectric means is comprised of a block of a dielectric material having the shape of a cylinder, and the second dielectric means is comprised of a block of a dielectric material having the shape of a cylinder. 
     
     
       3. The bandstop filter according to claim 1, wherein the first dielectric means is comprised of a block of a dielectric material having the shape of a parallelepiped, and the second dielectric means is comprised of a block of a dielectric material having the shape of a parallelepiped. 
     
     
       4. The bandstop filter according to claim 1, further including a signal source for generating an input signal with respect to signal ground, means for coupling the input signal to the electrode means on the top surface of the first dielectric means, and means for coupling the plated portion of the second dielectric means to signal ground. 
     
     
       5. The bandstop filter according to claim 4, further including shunt capacitive means coupled between the input signal and signal ground. 
     
     
       6. The bandstop filter according to claim 5, wherein said shunt capacitive means includes first electrode means comprised of a conductive material disposed on the top surface of the first dielectric means and second electrode means comprised of a conductive material disposed on the bottom surface of the first dielectric means substantially opposite to the first electrode means, the first electrode means being coupled to the electrode means of the first dielectric means, and the second electrode means being coupled to signal ground. 
     
     
       7. The bandstop filter according to claim 4, further including shunt inductive means coupled between the input signal and signal ground. 
     
     
       8. The bandstop filter according to claim 7, wherein said shunt inductive means includes strip electrode means comprised of a conductive material disposed on the top surface of the first dielectric means, one end of the strip electrode means being coupled to the electrode means of the first dielectric means, and the other end of the strip electrode means being coupled to signal ground. 
     
     
       9. The bandstop filter according to claim 1, wherein the electrode means on the top surface of the first dielectric means includes a plurality of fingers intercoupled at one end. 
     
     
       10. The bandstop filter according to claim 9, adapted to be tuned to attenuate a pre-selected range of frequencies by tuning means, said tuning means including means for triming the fingers of the electrode means for tuning said bandstop filter. 
     
     
       11. A bandstop filter comprising: means comprised of a dielectric material and having top and bottom surfaces, said dielectric means further including a hole extending from the top surface to the bottom surface thereof, and said dielectric means further being covered entirely with a conductive material with the exception of the top surface; and   capacitive means including electrode means comprised of a conductive material disposed on the top surface of the dielectric means at a predetermined distance from the hole in the dielectric means.   
     
     
       12. The bandstop filter according to claim 11, wherein the dielectric means is comprised of a block of a dielectric material having the shape of a cylinder. 
     
     
       13. The bandstop filter according to claim 11, wherein the dielectric means is comprised of a block of a dielectric material having the shape of a parallelepiped. 
     
     
       14. The bandstop filter according to claim 11, further including a signal source for generating an input signal with respect to signal ground, means for coupling the input signal to the electrode means on the top surface of the dielectric means, and means for coupling the plated portion of the dielectric means to signal ground. 
     
     
       15. The bandstop filter according to claim 14, further including shunt capacitive means coupled between the input signal and signal ground. 
     
     
       16. The bandstop filter according to claim 15, wherein said shunt capacitive means includes electrode means comprised of a conductive material disposed on the top surface of the dielectric means at a predetermined distance from the electrode means of the capacitive means and being coupled to signal ground. 
     
     
       17. The bandstop filter according to claim 16, adapted to be tuned to pass a pre-selected range of frequencies by tuning means, said tuning means including means for trimming the electrode means of the shunt capacitive means for tuning said bandstop filter. 
     
     
       18. The bandstop filter according to claim 14, further including shunt inductive means coupled between the input signal and signal ground. 
     
     
       19. The bandstop filter according to claim 18, wherein said shunt inductive means including strip electrode means comprised of a conductive material disposed on the top surface of the dielectric means, one end of the strip electrode means being coupled to the electrode means of the capacitive means, and the other end of the strip electrode means being coupled to signal ground. 
     
     
       20. The bandstop filter according to claim 19, adapted to be tuned to pass a pre-selected range of frequencies by tuning means, said tuning means including means for triming the strip electrode means of the shunt inductive means for tuning said bandstop filter. 
     
     
       21. The bandstop filter according to claim 11, adapted to be tuned to attenuate a pre-selected range of frequencies, said tuning means including means for triming the electrode means of the capacitive means. 
     
     
       22. A bandpass/bandstop filter comprising: first means comprised of a dielectric material and having parallel, flat, top and bottom surfaces, said first dielectric means further including input electrode means comprised of a conductive material plated on the top surface;   second means comprised of a dielectric material and having parallel, flat, top and bottom surfaces, said second dielectric means further including a hole extending from the top surface to the bottom surface thereof, and said second dielectric means further being plated entirely with a conductive material with the exception of the top surface;   means for attaching the bottom surface of the first dielectric means to the top surface of the second dielectric means so that the input electrode means on the top surface of the first dielectric means is arranged substantially opposite to the hole in the second dielectric means; and   shunt capacitive means coupled between the input electrode means on the top surface of the first dielectric means and signal ground.   
     
     
       23. The bandstop/bandpass filter according to claim 22, wherein the first dielectric means is comprised of a block of a dielectric material having the shape of a cylinder, and the second dielectric means is comprised of a block of a dielectric material having the shape of a cylinder. 
     
     
       24. The bandstop/bandpass filter according to claim 22, wherein the first dielectric means is comprised of a block of a dielectric material having the shape of a parallelepiped, and the second dielectric means is comprised of a block of a dielectric material having the shape of a parallelepiped. 
     
     
       25. The bandstop/bandpass filter according to claim 22, further including a signal source for generating an input signal with respect to signal ground, means for coupling the input signal to the input electrode means on the top surface of the first dielectric means, and means for coupling the plated portion of the second dielectric means to signal ground. 
     
     
       26. The bandstop/bandpass filter according to claim 22, wherein said shunt capacitive means includes first electrode means comprised of a conductive material plated on the top surface of the first dielectric means and second electrode means comprised of a conductive material plated on the bottom surface of the first dielectric means substantially opposite to the first electrode means, the first electrode means being coupled to the input electrode means, and the second electrode means being coupled to signal ground. 
     
     
       27. A bandstop/bandpass filter comprising: first means comprised of a dielectric material and having parallel, flat, top and bottom surfaces, said first dielectric means further including input electrode means comprised of a conductive material plated on the top surface;   second means comprised of a dielectric material and having parallel, flat, top and bottom surfaces, said second dielectric means further including a hole extending from the top surface to the bottom surface thereof, and said second dielectric means further being plated entirely with a conductive material with the exception of the top surface;   means for attaching the bottom surface of the first dielectric means to the top surface of the second dielectric means so that the input electrode means on the top surface of the first dielectric means is arranged substantially opposite to the hole in the second dielectric means; and   shunt inductive means coupled between the input electrode means on the top surface of the first dielectric means and signal ground.   
     
     
       28. The bandstop/bandpass filter according to claim 27, wherein the first dielectric means is comprised of a block of a dielectric material having the shape of a cylinder, and the second dielectric means is comprised of a block of a dielectric material having the shape of a cylinder. 
     
     
       29. The bandstop/bandpass filter according to claim 27, wherein the first dielectric means is comprised of a block of a dielectric material having the shape of a parallelepiped, and the second dielectric means is comprised of a block of a dielectric material having the shape of a parallelepiped. 
     
     
       30. The bandstop/bandpass filter according to claim 27, further including a signal source for generating an input signal with respect to signal ground, means for coupling the input signal to the input electrode means on the top surface of the first dielectric means, and means for coupling the plated portion of the second dielectric means to signal ground. 
     
     
       31. The bandstop/bandpass filter according to claim 27, wherein said shunt inductive means includes strip electrode means comprised of a conductive material plated on the top surface of the first dielectric means, one end of the strip electrode means being coupled to the input electrode means, and the other end of the strip electrode means being coupled to signal ground. 
     
     
       32. A bandstop filter comprising: means comprised of a dielectric material and having parallel, flat, top and bottom surfaces, said dielectric means further including a hole extending from the top surface to the bottom surface thereof, and said dielectric means further being plated entirely with a conductive material with the exception of the top surface;   capacitive means including electrode means comprised of a conductive material plated on the top surface of the dielectric means at a predetermined distance from the hole in the dielectric means; and   shunt capacitive means coupled between the electrode means and signal ground.   
     
     
       33. The bandstop filter according to claim 32, wherein the dielectric means is comprised of a block of a dielectric material having the shape of a cylinder. 
     
     
       34. The bandstop filter according to claim 32, wherein the dielectric means is comprised of a block of a dielectric material having the shape of a parallelepiped. 
     
     
       35. The bandstop filter according to claim 32, further including a signal source for generating an input signal with respect to signal ground, means for coupling the input signal to the electrode means on the top surface of the dielectric means, and means for coupling the plated portion of the dielectric means to signal ground. 
     
     
       36. The bandstop filter according to claim 32, wherein said shunt capacitive means includes electrode means comprised of a conductive material plated on the top surface of the dielectric means at a predetermined distance from the electrode means of the capacitive means and being coupled to signal ground. 
     
     
       37. A bandstop filter comprising: means comprised of a dielectric material and having parallel, flat, top and bottom surfaces, said dielectric means further including a hole extending from the top surface to the bottom surface thereof, and said dielectric means further being plated entirely with a conductive material with the exception of the top surface;   capacitive means including electrode means comprised of a conductive material plated on the top surface of the dielectric means at a predetermined distance from the hole in the dielectric means; and   shunt inductive means coupled between the electrode means and signal ground.   
     
     
       38. The bandstop filter according to claim 37, wherein the dielectric means is comprised of a block of a dielectric material having the shape of a cylinder. 
     
     
       39. The bandstop filter according to claim 37, wherein the dielectric means is comprised of a block of a dielectric material having the shape of a parallelepiped. 
     
     
       40. The bandstop filter according to claim 37, further including a signal source for generating an input signal with respect to signal ground, means for coupling the input signal to the electrode means on the top surface of the dielectric means, and means for coupling the plated portion of the dielectric means to signal ground. 
     
     
       41. The bandstop filter according to claim 37, wherein said shunt inductive means including strip electrode means comprised of a conductive material plated on the top surface of the dielectric means, one end of the strip electrode means being coupled to the input electrode means, and the other end of the strip electrode means being coupled to signal ground. .Iadd. 
     
     
       42.  A transmission line device comprising: first means comprised of a dielectric material and having top, bottom and side surfaces, said first dielectric means further including electrode means disposed on the top surface;   second means comprised of a dielectric material and having top, bottom, side and internal surfaces, said internal surface produced by a hole extending from the top surface toward the bottom surface of said second dielectric means, and portions of the surfaces of said second dielectric means further being covered with a conductive material for producing a transmission line; and   means for attaching the bottom surface of the first dielectric means to the top surface of the second dielectric means so that said first and second dielectric means are attached together and at least a portion of the electrode means is arranged substantially opposite to the hole in the second dielectric means. .Iaddend. .Iadd.   
     
     
       43.  The transmission line device according to claim 42, wherein the first dielectric means is comprised of a block of a dielectric material having the shape of cylinder, and the second dielectric means is comprised of a block of a dielectric material having the shape of a cylinder. .Iaddend. .Iadd.44. The transmission line device according to claim 42, wherein the first dielectric means is comprised of a block of a dielectric material having the shape of a parallelepiped, and the second dielectric means is comprised of a block of a dielectric material having the shape of a parallelepiped. .Iaddend. .Iadd.45. The transmission line device according to claim 42, further including a signal source for generating an input signal with respect to signal ground, means for coupling the input signal to the electrode means on the top surface of the first dielectric means, and means for coupling the plated portion of the second dielectric means to signal ground. .Iaddend. .Iadd.46. The transmission line device according to claim 42, further including second electrode means disposed on the top surface of the second dielectric means. .Iaddend. .Iadd.47. The transmission line device according to claim 46, wherein said second electrode means is coupled to said conductive material. .Iaddend. .Iadd.48. The transmission line device according to claim 42, further including shunt capacitive means coupled between the electrode means and signal ground. .Iaddend. .Iadd.49. The transmission line device according to claim 48, wherein said shunt capacitive means includes first electrode means disposed on the top surface of the first dielectric means and second electrode means disposed on the bottom surface of the first dielectric means substantially opposite to the first electrode means, the first electrode means being coupled to the electrode means of the first dielectric means, and the second electrode means being coupled to signal ground. .Iaddend. .Iadd.50. The transmission line device according to claim 42, further including shunt inductive means coupled between the electrode means and signal ground. .Iaddend. .Iadd.51. The transmission line device according to claim 50, wherein said shunt inductive means includes strip electrode means disposed on the top surface of the first dielectric means, one end of the strip electrode means being coupled to the electrode means of the first dielectric means, and the other end of the strip electrode means being coupled to signal ground. .Iaddend. .Iadd.52. The transmission line device according to claim 42, wherein the electrode means on the top surface of the first dielectric means includes 
     
     
        a plurality of fingers intercoupled at one end. .Iaddend. .Iadd.53.  A transmission line device comprising: means comprised of a dielectric material and having top, bottom, side and internal surfaces, said internal surface produced by a hole extending from the top surface toward the bottom surface of the dielectric means, and the bottom, side and internal surfaces of said dielectric means further being covered entirely with a conductive material for producing a transmission line; and   capacitive means including electrode means disposed on the top surface of the dielectric means at a predetermined distance from the hole in the   
     
     
        dielectric means. .Iaddend. .Iadd.54.  The transmission line device according to claim 53, wherein the dielectric means is comprised of a block of dielectric material having the shape of cylinder. .Iaddend. .Iadd.55. The transmission line device according to claim 53, wherein the dielectric means is comprised of a block of dielectric material having the shape of a parallelepiped. .Iaddend. .Iadd.56. The transmission line device according to claim 53, further including a signal source for generating an input signal with respect to signal ground, means for coupling the input signal to the electrode means on the top surface of the dielectric means, and means for coupling said conductive material to 
     
     
        signal ground. .Iaddend. .Iadd.57.  The transmission line device according to claim 53, further including shunt capacitive means coupled between the electrode means and signal ground. .Iaddend. .Iadd.58. The transmission line device according to claim 57, wherein said shunt capacitive means includes electrode means disposed on the top surface of the dielectric means at a predetermined distance from the electrode means of the 
     
     
        capacitive means and being coupled to signal ground. .Iaddend. .Iadd.59. The transmission line device according to claim 53, further including shunt capacitive means coupled between the hole in the dielectric means and signal ground. .Iaddend. .Iadd.60. The transmission line device according to claim 59, wherein said shunt capacitive means includes electrode means at a predetermined distance from the hole in the dielectric means and being coupled to signal ground. .Iaddend. .Iadd.61. The transmission line device according to claim 53, further including shunt inductive means coupled between the electrode means and signal ground. .Iaddend. .Iadd.62. The transmission line device according to claim 61, wherein said shunt inductive means includes strip electrode means comprised of a conductive material disposed on the top surface of the dielectric means, one end of the strip electrode means being coupled to the electrode means of the capacitive means, and the other end of the 
     
     
        strip electrode means being coupled to signal ground. .Iaddend. .Iadd.63. A filter having a passband of frequencies, comprising: first means comprised of a dielectric material and having top and bottom surfaces, said first dielectric means further including electrode means comprised of a conductive material disposed on the top surface;   second means comprised of a dielectric material and having top and bottom surfaces, said second dielectric means further including a hole extending from the top surface to the bottom surface thereof, and said second dielectric means further being covered entirely with a conductive material with the exception of the top surface; and   means for attaching the bottom surface of the first dielectric means to the top surface of the second dielectric means so that the electrode means on the top surface of the first dielectric means is arranged substantially   
     
     
        opposite to the hole in the second dielectric means. .Iaddend. .Iadd.64. The filter according to claim 63, wherein the first dielectric means is comprised of a block of a dielectric material having the shape of a cylinder, and the second dielectric means is comprised of a block of a dielectric material having the shape of a cylinder. .Iaddend. .Iadd.65. The filter according to claim 63, wherein the first dielectric means is comprised of a block of a dielectric material having the shape of a parallelepiped, and the second dielectric means is comprised of a block of a dielectric material having the shape of a parallelepiped. .Iaddend. .Iadd.66. The filter according to claim 63, further including a signal source for generating an input signal with respect to signal ground, means for coupling the input signal to the electrode means on the top surface of the first dielectric means, and means for coupling the conductive material covering the second dielectric means to signal ground. .Iaddend. .Iadd.67. The filter according to claim 63, further including shunt capacitive means coupled between the electrode means and signal ground. .Iaddend. 
     
     
        .Iadd.     The filter according to claim 67, wherein said shunt capacitive means includes first electrode means comprised of a conductive material disposed on the top surface of the first dielectric means and second electrode means comprised of a conductive material disposed on the bottom surface of the first dielectric means substantially opposite to the first electrode means, the first electrode means being coupled to the electrode means of the first dielectric means, and the second electrode means being coupled to signal ground. .Iaddend. .Iadd.69. The filter according to claim 63, further including shunt inductive means coupled between the electrode means and signal ground. .Iaddend. .Iadd.70. The filter according to claim 69, wherein said shunt inductive means includes strip electrode means comprised of a conductive material disposed on the top surface of the first dielectric means, one end of the strip electrode means being coupled to the electrode means of the first dielectric means, and the other end of the strip electrode means being coupled to signal ground. .Iaddend. .Iadd.71. The filter according to claim 63, wherein the electrode means on the top surface of the first dielectric means includes 
     
     
        a plurality of fingers intercoupled at one end. .Iaddend. .Iadd.72.  A radio, comprising in combination: an antenna;   a transmitter;   a receiver;   an antenna duplexer for coupling said receiver to said antenna and coupling said transmitter to said antenna, said antenna duplexer further including at least one transmission line device comprising:   first means comprised of a dielectric material and having top, bottom and side surfaces, said first dielectric means further including electrode means disposed on the top surface;   second means comprised of a dielectric material and having top, bottom, side and internal surfaces, said internal surface produced by a hole extending from the top surface toward the bottom surface of said second dielectric means, and portions of the surfaces of said second dielectric means further being covered with a conductive material for producing a transmission line; and   means for attaching the bottom surface of the first dielectric means to the top surface of the second dielectric means so that said first and second dielectric means are attached together and at least a portion of the electrode means is arranged substantially opposite to the hole in the   
     
     
        second dielectric means. .Iaddend. .Iadd.73.  A radio, comprising in combination: an antenna;   a transmitter;   a receiver;   an antenna duplexer for coupling said receiver to said antenna and coupling said transmitter to said antenna, said antenna duplexer further including at least one transmission line device comprising:   means comprised of a dielectric material and having top, bottom, side and internal surfaces, said internal surface produced by a hole extending from the top surface toward the bottom surface of the dielectric means, and the bottom, side and internal surfaces of said dielectric means further being covered entirely with a conductive material for producing a transmission line; and   capacitive means including electrode means disposed on the top surface of the dielectric means at a predetermined distance from the hole in the   
     
     
        dielectric means. .Iaddend. .Iadd.74.  An antenna duplexer for coupling a radio to an antenna, said antenna duplexer further including at least one transmission line device comprising: first means comprised of a dielectric material and having top, bottom and side surfaces, said first dielectric means further including electrode means disposed on the top surface;   second means comprised of a dielectric material and having top, bottom, side and internal surfaces, said internal surface produced by a hole extending from the top surface toward the bottom surface of said second dielectric means, and portions of the surfaces of said second dielectric means further being covered with a conductive material for producing a transmission line; and   means for attaching the bottom surface of the first dielectric means to the top surface of the second dielectric means so that said first and second dielectric means are attached together and at least a portion of the electrode means is arranged substantially opposite to the hole in the second dielectric means. .Iaddend.