Parallel coupled CPW line filter

Abstract

A parallel coupled CPW line filter is provided, including a first and a second coupled lines arranged on one side of an insulating body and connected in parallel with each other, and a ground arranged on the same plane as the first and the second coupled lines, comprising a pair of ground parts spaced apart from the first and the second coupled lines, respectively, the ground parts each comprising recesses sunken from areas close to the first and the second coupled lines.

Description

BRIEF DESCRIPTION OF THE DRAWING FIGURES

The above and other aspects of the present invention will be more apparent by describing certain exemplary embodiments of the present invention with reference to the accompanying drawings, in which:

FIG. 1 is a perspective view of a related parallel coupled line filter having an aperture;

FIG. 2A shows a sectional view and an equivalent circuit diagram when electric current flows along the parallel coupled line filter of FIG. 1 in the same direction;

FIG. 2B shows a sectional view and an equivalent circuit diagram when electric current flows along the parallel coupled line filter of FIG. 1 in opposite directions;

FIG. 3A is a sectional view of a parallel coupled CPW line filter according to a first exemplary embodiment of the present invention;

FIG. 3B is a plan view of the parallel coupled CPW line filter of FIG. 3A;

FIG. 4 is a plan view of a parallel coupled CPW line filter according to a second exemplary embodiment of the present invention;

FIG. 5 is a graphical expression of losses of the parallel coupled CPW line filter of FIG. 4;

FIG. 6 is a graphical expression of a normalized J-inverter of the parallel coupled CPW line filter of FIG. 4;

FIG. 7 is a graphical expression illustrating the relations between the length of the first and the second coupled lines and the frequency band in the parallel coupled CPW line filter of FIG. 4;

FIG. 8 is a plan view of a parallel coupled CPW line filter according to a third exemplary embodiment of the present invention;

FIG. 9 is a graphical expression illustrating losses of the parallel coupled CPW line filter of FIG. 8;

FIG. 10 is a plan view of a parallel coupled CPW line filter according to a fourth exemplary embodiment of the present invention; and

FIG. 11 is a graphical expression of losses of the parallel coupled CPW line filter of FIG. 10.

Claims

1. A parallel coupled CPW line filter, comprising: a first and a second coupled lines arranged in parallel on one side of an insulating body; anda ground forming a coupling with the first and the second coupled lines, and arranged on the same plane as the first and the second coupled lines.

2. The parallel coupled CPW line filter of claim 1, wherein the ground comprises a pair of ground parts arranged around the first and the second coupled lines which are spaced apart from the first and the second coupled lines, respectively.

3. The parallel coupled CPW line filter of claim 2, wherein the pair of ground parts each comprise recesses sunken from areas close to the first and the second coupled lines.

4. The parallel coupled CPW line filter of claim 3, wherein the first and the second coupled lines are extended from opposite ends of the insulating body and bent a plurality of times in a substantially zigzag fashion between the pair of ground parts.

5. The parallel coupled CPW line filter of claim 4, wherein heads of the first and the second lines facing each other are spaced apart from each other and arranged in parallel.

6. The parallel coupled CPW line filter of claim 5, wherein the length of the first and the second coupled lines is λ/4.

7. The parallel coupled CPW line filter of claim 6, comprising a pair of supplementary coupled lines bent in a substantially zigzag fashion in the same direction as the first and the second coupled lines, and arranged in parallel with the first and the second coupled lines.

8. The parallel coupled CPW line filter of claim 7, wherein one of the first and the second coupled lines and one of the supplementary coupled lines are connected with each other by a connecting area.

9. The parallel coupled CPW line filter of claim 8, wherein the total length of one of the first and the second coupled lines, one of the supplementary coupled lines, and the connecting area is λ/2.

10. The parallel coupled CPW line filter of claim 9, further comprising an open stub comprising a vertical strip elongated from the connecting area along the lengthwise direction of the first and the second coupled lines, and a horizontal strip arranged at one end of the vertical strip.

11. The parallel coupled CPW line filter of claim 10, wherein the open stub comprises a pair of symmetrical open stubs with respect to the connecting area.

12. A parallel coupled CPW line filter, comprising: a first and a second coupled lines arranged on one side of an insulating body and arranged in parallel with each other; anda ground arranged on the same plane as the first and the second coupled lines, comprising a pair of ground parts spaced apart from the first and the second coupled lines, respectively, the ground parts each comprising recesses sunken from areas close to the first and the second coupled lines.

13. A parallel coupled CPW line filter, comprising: a first and a second coupled lines arranged on one side of an insulating body in parallel with each other, and extended from opposite ends of the insulating body and bent a plurality of times in a substantially zigzag fashion crossing the lengthwise direction; anda ground arranged on the same plane as the first and the second coupled lines, comprising a pair of ground parts spaced apart from the first and the second coupled lines, respectively, the ground parts each comprising recesses sunken from areas close to the first and the second coupled lines.