Antenna impedance matching circuit, antenna system and mobile terminal

Patent metadata

Field	Value
Publication number	US-12150241-B2
Application number	US-201917615843-A
Country	US
Kind code	B2
Filing date	Dec 18, 2019
Priority date	Dec 3, 2019
Publication date	Nov 19, 2024
Grant date	Nov 19, 2024

Abstract

Disclosed is an antenna impedance matching circuit, an antenna system, a printed circuit board, and a terminal. The antenna impedance matching circuit comprises: a first transmission line having a first specific length such that the first transmission line is capacitive, and a second transmission line having a second specific length such that the second transmission line is inductive. In particular, the first transmission line and the second transmission line are connected in parallel, and terminals of the first transmission line and the second transmission line are open or shorted.

First claim

What is claimed is:

1. An antenna impedance matching circuit comprising:
a first transmission line, wherein the first transmission line having a first specific length that makes the first transmission line capacitive; and
a second transmission line, wherein the second transmission line having a second specific length that makes the second transmission line inductive;
wherein the first transmission line and the second transmission line are connected in parallel and wherein terminals of the first transmission line and the second transmission line are open or shorted;
the antenna impedance matching circuit comprises:
a first line connected in parallel with a line containing an antenna feeder line, for holding the first transmission line having the first specific length; and
a second line connected in parallel with the line containing the antenna feeder line, for holding the second transmission line having the second specific length;
wherein a terminal of the first line is configured to enclose the terminal of the first transmission line to unground the first transmission line, or is configured to be open to ground the first transmission line, and a terminal of the second line is configured to enclose the terminal of the second transmission line to unground the second transmission line, or is configured to be open to ground the second transmission line.

2. The antenna impedance matching circuit according to claim 1 , wherein
both the first transmission line and the second transmission line have a width of 0.2-0.3 mm.

3. The antenna impedance matching circuit according to claim 1 , wherein impedance of the first transmission line and the second transmission line are both 50 ohms.

4. The antenna impedance matching circuit according to claim 1 , wherein
the antenna impedance matching circuit is mounted on a printed circuit board, and a second layer of the printed circuit board is partially clear below the first line and the second line.

5. The antenna impedance matching circuit according to claim 1 , wherein
the first line and the second line are at a distance of 0.1-0.2 mm from ground.

6. The antenna impedance matching circuit according to claim 1 , wherein
the antenna impedance matching circuit is mounted on a printed circuit board, and a distance between the first and second lines and a location of an antenna latch on the printed circuit board is less than 5 mm.

7. An antenna system comprising
an antenna and a circuit board, wherein the circuit board comprises a printed circuit board and an antenna impedance matching circuit, wherein the antenna impedance matching circuit is mounted on the printed circuit board, the printed circuit board is applied to an antenna system comprising an antenna and the antenna impedance matching circuit;
wherein the antenna impedance matching circuit comprises: a first transmission line having a first specific length that makes the first transmission line capacitive, and a second transmission line having a second specific length that makes the second transmission line inductive, wherein the first transmission line and the second transmission line are connected in parallel, and terminals of the first transmission line and the second transmission line are open or shorted;
the printed circuit board comprises: a first line connected in parallel with a line containing an antenna feeder line, for holding the first transmission line having the first specific length, and a second line connected in parallel with the line containing the antenna feeder line, for holding the second transmission line having the second specific length;
wherein a terminal of the first line is configured to enclose the terminal of the first transmission line to unground the first transmission line, or is configured to be open to ground the first transmission line, and a terminal of the second line is configured to enclose the terminal of the second transmission line to unground the second transmission line, or is configured to be open to ground the second transmission line.

8. The printed circuit board according to claim 7 , wherein
a second layer of the printed circuit board is partially clear below the first line and the second line.

9. The printed circuit board according to claim 7 , wherein
the first line and the second line are at a distance of 0.1-0.2 mm from ground.

10. The printed circuit board according to claim 7 , wherein
a distance between the first and second lines and a location of an antenna latch on the printed circuit board is less than 5 mm.

11. The printed circuit board according to claim 7 , wherein
the first and second transmission lines are both 0.2-0.3 mm wide.

12. The printed circuit board according to claim 7 , wherein
both the first transmission line and the second transmission line have an impedance of 50 ohms.

13. A mobile terminal comprising
an antenna system, wherein the antenna system comprises an antenna and a circuit board, the circuit board comprises a printed circuit board and an antenna impedance matching circuit, the antenna impedance matching circuit is mounted on the printed circuit board;
wherein the antenna impedance matching circuit comprises: a first transmission line having a first specific length that makes the first transmission line capacitive, and a second transmission line having a second specific length that makes the second transmission line inductive, wherein the first transmission line and the second transmission line are connected in parallel, and terminals of the first transmission line and the second transmission line are open or shorted;
the printed circuit board comprises: a first line connected in parallel with a line containing an antenna feeder line, for holding the first transmission line having the first specific length, and a second line connected in parallel with the line containing the antenna feeder line, for holding the second transmission line having the second specific length;
wherein a terminal of the first line is configured to enclose the terminal of the first transmission line to unground the first transmission line, or is configured to be open to ground the first transmission line, and a terminal of the second line is configured to enclose the terminal of the second transmission line to unground the second transmission line, or is configured to be open to ground the second transmission line.

14. The mobile device according to claim 13 , wherein
the mobile device is one of the following: a mobile phone, a tablet, a laptop, a smart watch, a smart bracelet, or a smart wearable device.

15. The mobile terminal according to claim 13 , wherein
a second layer of the printed circuit board is partially clear below the first line and the second line.

16. The mobile terminal according to claim 13 , wherein
the first line and the second line are at a distance of 0.1-0.2 mm from ground.

17. The mobile terminal according to claim 13 , wherein
a distance between the first and second lines and a location of an antenna latch on the printed circuit board is less than 5 mm.

18. The mobile terminal according to claim 13 , wherein
the first and second transmission lines are both 0.2-0.3 mm wide.

19. The mobile terminal according to claim 13 , wherein
both the first transmission line and the second transmission line have an impedance of 50 ohms.

Assignees

• Huizhou Tcl Mobile Communication Co Ltd

Inventors

• Chen Wei
• Hou Junsheng
• Bai Song

Classifications

• H01Q5/50

  Feeding or matching arrangements for broad-band or multi-band operation · CPC title

• H03H7/38

  Impedance-matching networks · CPC title

• H01P5/16

  Conjugate devices, i.e. devices having at least one port decoupled from one other port · CPC title

• H04B1/18 Primary

  Input circuits, e.g. for coupling to an antenna or a transmission line (coupling networks between antennas or lines and receivers independent of the nature of the receiver H03H) · CPC title

• H05K1/0243

  Printed circuits associated with mounted high frequency components · CPC title