Tunable electronic circuit which converts balanced signals to unbalanced signals

摘要

Balun with tunable bandpass filter characteristic includes first, second and third coupling elements disposed on a substrate. The first and second coupling elements are arranged on the substrate relative to the third coupling element to couple two identical but out of phase signals to form a corresponding unbalanced signal in the third coupling element. A plurality of tunable resonator elements are distributed within an area of the substrate defined on one side by the first and second coupling elements and on an opposing side by the third coupling element. The tunable resonator elements are configured to selectively produce a bandpass filter response.

主权项

1. A tunable electronic circuit, comprising:
a substrate formed of a dielectric material; a balanced signal transmission structure includes first and second coupling elements which are disposed on a first major surface of the substrate, each symmetrically connected at one end to a signal ground defined by a ground plane disposed on an opposing second major surface of the substrate; an unbalanced signal transmission structure including a third coupling element disposed on the first major surface of the substrate and having one terminal end connected to the signal ground; the first and second coupling elements arranged on the substrate relative to the third coupling element to couple two identical but out of phase signals from the balanced signal transmission structure to the unbalanced signal transmission structure and thereby form a corresponding unbalanced signal in the third coupling element; a plurality of resonator elements distributed within an area of the substrate defined on one side by the first and second coupling elements and on an opposing side by the third coupling element, the plurality of resonator elements disposed on the first major surface of the substrate so as to be spaced apart from each other and from each of the first, second and third coupling elements; wherein the plurality of resonator elements are cooperatively configured to produce a bandpass filter response when signals are communicated between the balanced signal transmission structure and the unbalanced signal transmission structure.