LC-type dielectric filter

Claim 2

An LC-type filter, comprising: (a) a dielectric plate; and (b) a printed circuit on said dielectric plate, said printed circuit including: (1) a conductive layer forming a ground portion, (2) an input terminal, (3) an output terminal, (4) first and second strip lines forming a pair of distributed constant resonators, one end of each of said first and second strip lines being connected to said ground portion, (5) a first coupling circuit coupling an other end of said first strip line and said input terminal, (6) a second coupling circuit coupling an other end of said second strip line and said output terminal, and (7) a third coupling circuit coupling together said other ends of said first and second strip lines.

Claim 3

An LC-type filter according to claim 1, wherein each of said first, second, and third coupling circuits comprises a separate capacitance circuit which includes a pair of parallel line-shaped conductors plated on said dielectric plate.

Claim 4

An LC-type filter, comprising: (a) a dielectric plate having a first upper surface and having a first specific inductive capacitance; (b) a printed circuit on said dielectric plate, said printed circuit including: (1) a conductive layer forming a ground portion; (2) an input terminal, (3) an output terminal, (4) a first coupling circuit, and (5) a second coupling circuit; (c) at least one rectangular dielectric block on said dielectric plate, said dielectric block having a second upper surface and first and second side surfaces respectively extending from said first upper surface to said second upper surface, and having a second inductive capacitance higher than said first specific inductive capacitance; and (d) a strip line on said second upper surface and said first and second side surfaces, said strip line extending from said ground portion at a first end of said strip line successively along said first side surface, said second upper surface and said second side surface to said first upper surface at a second end of said strip line, said strip line and dielectric block forming a resonator, said first coupling circuit coupling said second end of said strip line to said input terminal, said second coupling circuit coupling said second end of said strip line to said output terminal.

Claim 5

An LC-type filter, comprising: (a) a dielectric plate having a first upper surface and having a first specific inductive capacitance; (b) a printed circuit on said dielectric plate, said printed circuit including: (1) a conductive layer forming a ground portion; (2) an input terminal, (3) an output terminal, (4) a first coupling circuit, and (5) a second coupling circuit; (c) at least one rectangular dielectric block on said dielectric plate, said dielectric block having a second upper surface and first and second side surfaces respectively extending from said first upper surface to said second upper surface, and having a second inductive capacitance higher than said first specific inductive capacitance; and (d) a strip line on said second upper surface and said first and second side surfaces, said strip line extending from said ground portion at a first end of said strip line successively along said first side surface, said second upper surface and said second side surface to said first upper surface at a second end of said strip line, said strip line and dielectric block forming a resonator, said first coupling circuit coupling said second end of said strip line to said input terminal, said second coupling circuit coupling said second end of said strip line to said output terminal.

Claim 6

An LC-type filter according to claim 3, wherein an other dielectric block having a strip line thereon is provided on said dielectric plate, the strip line on said other dielectric block having a first end connected to said ground portion and a second end, said printed circuit further comprising a third coupling circuit coupling together the second ends of the strip lines.

Claim 7

An LC-type dielectric filter, comprising: (a) a dielectric plate; (b) a conductive layer on said dielectric plate forming a ground portion; (c) an input terminal on said dielectric plate; (d) an output terminal on said dielectric plate; (e) at least one strip line on said dielectric plate, forming a distributed constant resonator, a first end of said strip line being connected to said ground portion; (f) a first coupling circuit on said dielectric plate, coupling a second end of said strip line to said input terminal; and (g) a second coupling circuit provided on said dielectric plate, coupling the second end of said strip line to said output terminal.

Claim 8

An LC-type dielectric filter, comprising: (a) a dielectric plate; (b) a conductive layer on said dielectric plate forming a ground portion; (c) an input terminal on said dielectric plate; (d) an output terminal on said dielectric plate; (e) at least one strip line on said dielectric plate, forming a distributed constant resonator, a first end of said strip line being connected to said ground portion; (f) a first coupling circuit on said dielectric plate, coupling a second end of said strip line to said input terminal; and (g) a second coupling circuit provided on said dielectric plate, coupling the second end of said strip line to said output terminal.

Claim 9

An LC-type filter according to claim 5, further comprising an other strip line having a first end connected to said ground portion and a second end and a third coupling circuit on said dielectric plate coupling together the second ends of the strip lines.