Patent ID: 7456702

Claim:
A coaxial filter comprising: a tubular outer conductor, having inner diameter, extending a given length from a first end to a second end distal from said first end, said inner diameter being in a direction perpendicular to a longitudinal center axis; an inner conductor arranged to extend substantially parallel to and collinear with said longitudinal center axis, such that an outer surface of said inner conductor and an inner surface of said tubular outer conductor define a cylindrical volume; and a filler material comprising a metal powder, said metal powder including a plurality of metallic particles, disposed in said cylindrical volume, wherein the inner diameter of the outer tubular conductor, the filler material, and the diameter of the inner conductor are constituted, structured and arranged to provide a characteristic impedance Z according to the formula Z = 138 K 1 / 2 ⁢ log ⁡ ( b / a ) , where K is the dielectric constant of said filler material, a is said diameter of the inner conductor, and b is said inside diameter of the outer tubular conductor.