US 12,176,591 B2 · Electrical filter structure

Abstract

An electrical filter structure for forwarding an electrical signal from a first port, e.g. P1, to a second port, e.g. P2, in a frequency selective manner, wherein the filter is a microwave filter, the electrical filter structure comprising: a plurality of pairs of an open stub and a short-circuited stub coupled electrically in parallel to a transmission line comprising a plurality of transmission line portions at a plurality of respective junctions between adjacent transmission line portions, e.g. Cross junction; and wherein the first port is connected with a first of the junctions having a first pair comprising a first open stub and a first short-circuited stub; wherein the second port is connected with a last of the junctions having a last pair comprising a last open stub and a last short-circuited stub; wherein lengths of the pair of the open stub and the short-circuited stub coupled to a same of the junctions are chosen such that electrical lengths of the open stub and short-circuited stub of the respective pairs are equal within a tolerance of +/−10%.

Claims19

Dependent claims

A microwave filter structure for forwarding an electrical signal from a first port to a second port in a frequency selective manner, the microwave filter structure comprising:

a plurality of pairs of an open stub and a short-circuited stub coupled in parallel, wherein the plurality of pairs is coupled electrically to a transmission line, and wherein the transmission line comprises a plurality of transmission line portions and wherein the plurality of pairs couple to the plurality of transmission line portions at a plurality of junctions between adjacent transmission line portions;
and
wherein the first port is coupled with a first junction of the plurality of junctions that is coupled to a first pair comprising a first open stub and a first short-circuited stub;
wherein the second port is coupled with a last junction of the plurality of junctions that is coupled to a last pair comprising a last open stub and a last short-circuited stub;
and
wherein lengths of a pair of an open stub and a short-circuited stub coupled to a same one of the plurality of junctions are sized such that electrical lengths of the open stub and short-circuited stub of a respective pair are longer by at least 2% than a fourth of a wavelength of a signal having a frequency of a passband center frequency of the microwave filter structure and equal within a tolerance of +/−10%.

3 more elements

An apparatus comprising:

an electrical filter operable to forward an electrical signal from a first port to a second port in a frequency selective manner, wherein the electrical filter is characterized as a microwave filter, and wherein the electrical filter further comprises:
a plurality of pairs of an open stub and a short-circuited stub coupled in parallel, wherein the plurality of pairs is coupled electrically to a transmission line, wherein the transmission line comprises a plurality of transmission line portions and wherein the plurality of pairs couple to the plurality of portions at a plurality of junctions between adjacent transmission line portions;
and
wherein the first port is coupled with a first junction of the plurality of junctions coupled to a first pair comprising a first open stub and a first short-circuited stub;
wherein the second port is coupled with a last junction of the plurality of junctions coupled to a last pair comprising a last open stub and a last short-circuited stub;
and
wherein lengths of a pair of an open stub and a short-circuited stub that are coupled to a same one of the plurality of junctions are sized wherein electrical lengths of the open stub and short-circuited stub of a respective pair are longer by at least 2% than a fourth of a wavelength of a signal having a frequency of a passband center frequency of the electrical filter.

4 more elements

An apparatus comprising:

an electrical filter for forwarding an electrical signal from a first port to a second port in a frequency selective manner, wherein the electrical filter comprises a microwave filter, and wherein the electrical filter further comprises:
a plurality of pairs of an open stub and a short-circuited stub coupled in parallel, wherein the plurality of pairs is coupled electrically to a transmission line, wherein the transmission line comprises a plurality of transmission line portions and wherein the plurality of pairs couple to the plurality of portions at a plurality of junctions between adjacent transmission line portions;
and
wherein the first port is connected with a first of the plurality of junctions coupled to a first pair comprising a first open stub and a first short-circuited stub;
wherein the second port is connected with a last of the plurality of junctions coupled to a last pair comprising a last open stub and a last short-circuited stub;
and
wherein lengths of the plurality of transmission line portions are sized wherein electrical lengths of each of the plurality of transmission line portions are shorter, by at least 10 percent, than a fourth of a wavelength of a signal having a frequency of a passband center frequency of the electrical filter;
and
wherein lengths of a pair of an open stub and a short-circuited stub that are coupled to a same one of the plurality of junctions are sized wherein electrical lengths of the open stub and short-circuited stub of a respective pair are longer by at least 2% than a fourth of a wavelength of a signal having a frequency of a passband center frequency of the electrical filter.

6 more elements

Dependencies are inferred from the claim text.

Electrical filter structure

Life of this patent

Electrical filter structure

Life of this patent

Abstract

Claims19