Ceramic bandpass filter

A filter comprising:

• means comprised of a dielectric material having parallel, flat, top and bottom surface, said dielectric means having at least two holes extending from the top surface toward the bottom surface thereof and spatially disposed at a predetermined distance from one another;
• first electrode means comprised of a conductive material plated on the top surface of the dielectric means at a predetermined distance from one of the holes in the dielectric means;
• second electrode means comprised of a conductive material plated on the top surface of the dielectric means at a predetermined distance from a hole other than said one of the holes in the dielectric means;
• and
• said dielectric means further being plated entirely with a conductive material with the exception of portions surrounding one end of said one hole and said other hole and surrounding the first and second electrode means, and the conductive material at said one end of each hole further being capacitively coupled to the surrounding conductive material whereby a foreshortened coaxial resonator is produced for each hole.

A filter comprising:

• means comprised of a dielectric material having a top surface, a bottom surface and first and second side surfaces, said dielectric means further having at least two holes extending from the top surface toward the bottom surface thereof and spatially disposed at a predetermined distance from one another;
• first electrode means comprised of a conductive material disposed on one of the first and second side surfaces of the dielectric means at a predetermined distance from the top surface and substantially opposite one of the holes in the dielectric means;
• second electrode means comprised of a conductive material disposed on one of the first and second side surfaces of the dielectric means at a predetermined distance from the top surface and substantially opposite a hole other than said one of the holes in the dielectric means;
• and
• said dielectric means further being entirely covered with a conductive material with the exception of portions surrounding one end of said one hole and said other hole and surrounding the first and second electrode means, and the conductive material at said one end of each hole further being capacitively coupled to the surrounding conductive material whereby a foreshortened coaxial resonator is produced for each hole.

A filter comprising:

• means comprised of a dielectric material having top and bottom surfaces, said dielectric means further having at least three holes extending from the top surface toward the bottom surface thereof and spatially disposed at a predetermined distance from one another, each of said holes having a predetermined amount of electrical coupling to each other hole;
• first electrode means comprised of a conductive material disposed on the dielectric means at a predetermined distance from one of the holes in the dielectric means;
• second electrode means comprised of a conductive material disposed on the dielectric means at a predetermined distance from a hole other than said one of the holes in the dielectric means;
• and
• said dielectric means further being entirely covered with a conductive material with the exception of portions surrounding one end of said one hole and said other hole and surrounding the first and second electrode means, and the conductive material at said one end of each hole further being capacitively coupled to the surrounding conductive material whereby a foreshortened coaxial resonator is produced for each hole.

A multi-band filter comprising:

• (a) first filtering means comprising:
• (i) means comprised of a dielectric material having top and bottom surfaces, said dielectric means further having at least two holes extending from the top surface toward the bottom surface thereof and spatially disposed at a predetermined distance from one another;
• (ii) first electrode means comprised of a conductive material disposed on the dielectric means at a predetermined distance from one of the holes in the dielectric means;
• (iii) second electrode means comprised of a conductive material disposed on the dielectric means at a predetermined distance from a hole other than said one of the holes in the dielectric means;
• and
• (iv) said dielectric means further being covered entirely with a conductive material with the exception of portions surrounding one end of said one hole and said other hole and surrounding the first and second electrode means, and the conductive material at said one end of each hole further being capacitively coupled to the surrounding conductive material whereby a foreshortened coaxial resonator is produced for each hole;
• and
• (b) second filtering means comprising:
• (i) means comprised of a dielectric material having top and bottom surfaces, said dielectric means further having at least two holes extending from the top surface toward the bottom surface thereof and spatially disposed at a predetermined distance from one another;
• (ii) first electrode means comprised of a conductive material disposed on the dielectric means at a predetermined distance from one of the holes in the dielectric means;
• (iii) second electrode means comprised of a conductive material disposed on the dielectric means at a predetermined distance from a hole other than said one of the holes in the dielectric means;
• and
• (iv) said dielectric means further being covered entirely with a conductive material with the exception of portions surrounding one end of said one hole and said other hole and surrounding the first and second electrode means, and the conductive material at said one end of each hole further being capacitively coupled to the surrounding conductive material whereby a foreshortened coaxial resonator is produced for each hole;
• and
• (c) means for coupling the first electrode means of the first filtering means to the first electrode means of the second filtering means.

A filter comprising:

• means comprised of a dielectric material having top and bottom surfaces, said dielectric means further having at least two holes extending from the top surface toward the bottom surface thereof and spatially disposed at a predetermined distance from one another;
• first electrode means comprised of a conductive material disposed at a predetermined distance from one of the holes in the dielectric means;
• second electrode means comprised of a conductive material disposed at a predetermined distance from a hole other than said one of the holes in the dielectric means;
• and
• said dielectric means further being covered with a conductive material with the exception of portions surrounding one end of said one hole and said other hole, and surrounding the first and second electrode means, and the conductive material at said one end of each hole further being capacitively coupled to the surrounding conductive material whereby a foreshortened coaxial resonator is produced for each hole.

A filter comprising:

• means comprised of a dielectric material having first and second surfaces, said dielectric means further having at least two holes extending from the first surface toward the second surface thereof and spatially disposed at a predetermined distance from one another;
• first coupling means associated with one of the holes in the dielectric means;
• second coupling means associated with a hole other than said one of the holes in the dielectric means;
• and
• said dielectric means further being covered with a conductive material with the exception of portions surrounding one end of said one hole and said other hole, and surrounding the first and second electrode means, and the conductive material at said one end of each hole further being capacitively coupled to the surrounding conductive material whereby a foreshortened coaxial resonator is produced for each hole.

A filter comprising:

• a block comprised of a dielectric material having first and second surfaces, said dielectric block further having at least two holes extending from the first surface toward the second surface thereof and spatially disposed at a predetermined distance from one another;
• a first electrode associated with one of the holes in the dielectric block;
• a second electrode associated with a hole other than said one of the holes in the dielectric block;
• and
• said dielectric block further being covered with a conductive material with the exception of portions surrounding one end of said one hole and said other hole, and surrounding the first and second electrode means, and the conductive material at said one end of each hole further being capacitively coupled to the surrounding conductive material whereby a foreshortened coaxial resonator is produced for each hole.

A filter comprising:

• means comprised of a dielectric material having top and bottom surfaces, said dielectric means further having at least two holes extending from the top surface toward the bottom surface thereof and spatially disposed at a predetermined distance from one another;
• first electrode means comprised of a conductive material disposed on the dielectric means at a predetermined distance from one of the holes in the dielectric means;
• second electrode means comprised of a conductive material disposed on the dielectric means at a predetermined distance from a hole other than said one of the holes in the dielectric means;
• and
• said dielectric means further including at least one slot between said one hole and said other hole for adjusting the electrical signal coupling from the first electrode means to the second electrode means, and said dielectric means further being covered with a conductive material with the exception of portions near the slot, near one end of said one hole and said other hole and near the first and second electrode means.

A filter comprising:

• means comprised of a dielectric material having parallel, flat, top and bottom surfaces, said dielectric means further having at least two holes extending from the top surface toward the bottom surface thereof and spatially disposed at a predetermined distance from one another;
• first electrode means comprised of a conductive material plated on the top surface of the dielectric means at a predetermined distance from one of the holes in the dielectric means;
• second electrode means comprised of a conductive material plated on the top surface of the dielectric means at a predetermined distance from a hole other than said one of the holes in the dielectric means;
• and said dielectric means further including at least one slot between said one hole and said other hole for adjusting the electrical signal coupling from the first electrode means to the second electrode means, and said dielectric means further being plated with a conductive material with the exception of portions near the slot, near one end of said one hole and said other hole and near the first and second electrode means.

A filter comprising:

• means comprised of a dielectric material having top and bottom surfaces, said dielectric means further having at least two holes extending from the top surface toward the bottom surface thereof and spatially disposed at a predetermined distance from one another;
• first electrode means comprised of a conductive material disposed at a predetermined distance from one of the holes in the dielectric means;
• second electrode means comprised of a conductive material disposed at a predetermined distance from a hole other than said one of the holes in the dielectric means;
• and
• said dielectric means further including at least one slot between said one hole and said other hole for adjusting the electrical signal from the first electrode means to the second electrode means, and said dielectric means further being covered with a conductive material with the exception of portions near the slot and near one end of said one hole and said outer hole.

A filter comprising:

• means comprised of a dielectric material having first and second surfaces, said dielectric means further having at least two holes extending from the first surface toward the second surface thereof and spatially disposed at a predetermined distance from one another;
• first coupling means associated with one of the holes in the dielectric means;
• second coupling means associated with a hole other than said one of the holes in the dielectric means;
• and
• said dielectric means further including at least one slot between said one hole and said other hole for adjusting the electrical signal coupling from the first coupling means to the second coupling means, and said dielectric means further being entirely covered with a conductive material with the exception of portions near the slot and near one end of said one hole and said other hole.

A method of adjusting the resonant frequency of a filter including means comprised of a dielectric material having first and second surfaces, said dielectric means further having at least two holes extending from the first surface toward the second surface thereof and spatially disposed at a predetermined distance from one another, first coupling means associated with one of the holes in the dielectric means, and second coupling means associated with a hole other than said one of the holes in the dielectric means, said method comprising the steps of:

• (a) covering the dielectric means with a conductive material with the exception of a first portion surrounding one end of said one hole and a second portion surrounding one end of said other hole;
• (b) covering part of said first portion and part of said second portion to produce a first electrode and a second electrode, respectively;
• and
• (c) removing a portion of the conductive material surrounding said one end of said one hole and said one end of said other hole to produce a pre-selected resonant frequency of said filter.

A method of adjusting the frequency response and resonant frequency of a filter including means comprised of a dielectric material having first and second surfaces, said dielectric means further having at least two holes extending from the first surface toward the second surface thereof and spatially disposed at a predetermined distance from one another, first coupling means associated with one of the holes in the dielectric means, and second coupling means associated with a hole other than said one of the holes in the dielectric means, said method comprising the steps of:

• (a) covering the dielectric means with a conductive material with the exception of a first portion surrounding one end of said one hole and a second portion surrounding one end of said other hole;
• (b) covering part of said first portion and part of said second portion to produce a first electrode and a second electrode, respectively;
• (c) removing a portion of the conductive material from the surface of the dielectric means between said one hole and said other hole to adjust the frequency response of said filter;
• and
• (d) removing a portion of the conductive material surrounding said one end of said one hole and said one end of said other hole to produce a pre-selected resonant frequency of said filter.

A method of adjusting the frequency response and resonant frequency of a filter including means comprised of a dielectric material having first and second surfaces, said dielectric means further having at least two holes extending from the first surface toward the second surface thereof and spatially disposed at a predetermined distance from one another, first coupling means associated with one of the holes in the dielectric means, and second coupling means associated with a hole other than said one of the holes in the dielectric means, said method comprising the steps of:

• (a) covering the dielectric means with a conductive material with the exception of a first portion surrounding one end of said one hole and a second portion surrounding one end of said other hole;
• (b) covering part of said first portion and part of said second portion to produce a first electrode and a second electrode, respectively;
• (c) removing a portion of the dielectric means between said one hole and said other hole to adjust the frequency response of said filter;
• and
• (d) removing a portion of the conductive material surrounding said one end of said one hole and said one end of said other hole to produce a pre-selected resonant frequency of said filter.

A filter comprising:

• means comprised of a dielectric material having top and bottom surfaces, said dielectric means further having at least two holes extending from the top surface toward the bottom surface thereof and spatially disposed at a predetermined distance from one another;
• first electrode means comprised of a conductive material disposed on the dielectric means at a predetermined distance from one of the holes in the dielectric means;
• second electrode means comprised of a conductive material disposed on the dielectric means at a predetermined distance from a hole other than said one of the holes in the dielectric means;
• and
• said dielectric means further being covered with a conductive material with the exception of portions surrounding one end of said one hole and said other hole and surrounding the first and second electrode means, and the conductive material at said one end of each hole further being overlapped on the surface of the dielectric means and capacitively coupled to the surrounding conductive material whereby a foreshortened coaxial resonator is produced for each hole.