Matching circuit for antennas
AssigneeKinneret Smart Waves Ltd. / KSW Antennas
InventorsMatti Martiskainen, Sharon Harel, Victor Hoepfner, Yaniv Ziv
Life of this patent
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Abstract
A matching circuit for matching an impedance of an antenna to an output impedance of a source circuit, the matching circuit includes a first band branch that is associated with a first frequency band, wherein the first band branch includes first band capacitors and first band inductors, wherein the first band capacitors and the first band inductors are configured to set impedances of the first band branch within the first band to fall on a loop that bypasses, within a Smith chart, a source Smith chart point representative of the output impedance of the source circuit.
Claims18
A matching circuit for matching an impedance of an antenna to an output impedance of a source circuit, the matching circuit includes a first band branch that is associated with a first frequency band, wherein the first band branch includes first band capacitors and first band inductors, wherein the first band capacitors and the first band inductors are configured to set impedances of the first band branch within the first band to fall on a loop that bypasses, within a Smith chart, a source Smith chart point representative of the output impedance of the source circuit.
According to an embodiment, (a) a maximal distance between the source Smith chart point and any of the impedances of the first band branch, is smaller than (b) a maximal distance between the source Smith chart point and any impedance of the antenna at an absence of the matching circuit.
According to an embodiment, (a) is smaller than (b) by a factor that exceeds two.
According to an embodiment, the one or more capacitors and one of more inductors form:
- a. a first band squeezing circuit configured to reduce a range of first band branch impedances related to the first band;
- b. a first band looping circuit configured to cause first branch impedances related to the first band to fall on the loop;
- and
- c. a first band stretching circuit configured to increase a range of first band branch impedances related to the first band.
According to an embodiment, an input of the first branch squeezing circuit is in communication with a first branch input;
- wherein an output of the first branch squeezing circuit is in communication with an input of the first band looping circuit;
- wherein an output of the first band looping circuit is in communication with an input of the first stretching circuit;
- and
- wherein an output of the first stretching circuit is in communication with a first branch output.
According to an embodiment, the first band squeezing circuit includes serially coupled first reactive impedance elements.
According to an embodiment, the first band stretching circuit includes serially coupled first reactive impedance elements.
According to an embodiment, the first band looping circuit includes a parallelly coupled first reactive impedance element.
According to an embodiment, the first band looping circuit includes a first band capacitor.
According to an embodiment, the first band stretching circuit includes a first band capacitor and a first band inductor that is serially coupled to the first band capacitor.
According to an embodiment, the first band stretching circuit includes a pair of serially coupled first band inductors.
According to an embodiment, the first band capacitors and the second band inductors consist essentially of three first band capacitors and two inductors.
The matching circuit according to further includes a second band branch that is associated with a second frequency band that differs from the first frequency band, wherein the second band branch includes second band capacitors and second band inductors, wherein the second band capacitors and the second band inductors are configured to set impedances of the second band branch within the second band to fall on another loop that bypasses, within the Smith chart, the source Smith chart point.
According to an embodiment, the first band branch is parallelly coupled to the second band branch.
According to an embodiment, the first band branch includes a second band stop filter, and the second band branch includes a first band stop filter.
According to an embodiment, a number of first band inductors differs from a number of second band inductors.
According to an embodiment, a number of first band inductors differs from a number of first band capacitor.
A method for impedance matching, the method includes:
- matching an impedance of an antenna to an output impedance of a source circuit by a matching circuit that includes a first band branch that is associated with a first frequency band, wherein the first band branch includes first band capacitors and first band inductors, wherein the first band capacitors and the first band inductors are configured to set impedances of the first band branch within the first band to fall on a loop that bypasses, within a Smith chart, a source Smith chart point representative of the output impedance of the source circuit.
Dependencies are inferred from the claim text.