Multi-band antenna

Patent metadata

Field	Value
Publication number	US-9711857-B2
Application number	US-201414880710-A
Country	US
Kind code	B2
Filing date	Apr 10, 2014
Priority date	Apr 12, 2013
Publication date	Jul 18, 2017
Grant date	Jul 18, 2017

Abstract

The present invention relates to multi-band antenna. This antenna comprises a substrate and at least one conductive layer provided with a plurality of antennas, such as PIFAs, resonating in specific frequency bands. The antennas are cascaded in order to achieve a compact antenna. The first antenna comprises a first radiating element, a first feed element connected to said first radiating element and a first ground return element and the second antennas comprises a second radiating element, a second feed element connected to said second radiating element and a second ground return element. The ground plane is printed in the same layer as the first or second antenna.

First claim

The invention claimed is:

1. A multi-band antenna comprising:
a substrate having at least one conductive layer;
said at least one conductive layer comprising
a ground section;
a first radiating element, a first feed element connected to said first radiating element and a first ground return element connected to said first radiating element and said ground section, said first radiating element and said first feed element being offset transversally from the ground section, said first radiating element, said first feed element and said first ground return element being arranged to form a first antenna resonating in a first frequency band,
a second radiating element, a second feed element connected to said second radiating element and a second ground return element connected to said second radiating element and said first ground return element, and said ground section, said second radiating element, said second feed element and said second ground return element are arranged to form a second antenna resonating in a second frequency band;
the length L 20 of the second radiating element being different from the length L 30 of the first radiating element, said second radiating element and said second feed element being offset transversally from said first radiating element and said first feed element; wherein the first feed element is connected to the second feed element by a link, such that the second radiating element is connected via the first feed element to a common feeding port; and
a third conductive layer of the substrate arranged between first and second conductive layers, said third conductive layer comprising a third radiating element, a third feed element connected to said third radiating element and a third ground return element connected to said third radiating element and said ground section, the length L 40 of the third radiating element being different from the lengths L 30 , L 20 of said first and second radiating elements, said third radiating element and said third feed element being offset transversally from said first and second radiating elements, said first and second feed elements and said ground section, wherein said third radiating element, said third feed element and said third ground return element being arranged to form a third antenna resonating in a third frequency band.

2. The multi-band antenna according to claim 1 wherein the substrate is provided with a first conductive layer and a second conductive layer separated from each other by said substrate wherein the ground section and the first antenna are provided in the first conductive layer and the second antenna is provided in the second conductive layer.

3. The multi-band antenna according to claim 2 , wherein the link comprises a microstrip line printed in the second conductive layer and is connected to the first conductive layer by at least one through connector, said microstrip line being arranged below or above the first radiating element.

4. The multi-band antenna according to a claim 1 , wherein the first ground return element is connected to the ground section by at least one through connector.

5. The multi-band antenna according to claim 4 , wherein the second ground return element is connected to the first ground return element by said at least one through connector.

6. The multi-band antenna according to claim 1 , wherein the first radiating element is a straight conductive line.

7. The multi-band antenna according to claim 1 , wherein the first radiating element comprises first and second successive straight portions the second portion) being perpendicular to the first portion.

8. The multi-band antenna according to claim 1 , wherein the length L 30 of the first radiating element is greater than the length L 20 of the second radiating element such that the second frequency band is higher than the first frequency band.

9. The multi-band antenna according to claim 1 , wherein the length L 31 and the width W 31 of the first feed element are defined to match the impedance of the first antenna with the impedance of a radio frequency circuit connected to the first feed element.

10. The multi-band antenna according to claim 9 , wherein the first feed element is connected to the radio frequency circuit via an inductor cascaded with a capacitor, the inductance of the inductor being determined in order to achieve impedance matching of the second antenna with the radio frequency circuit and the capacitance of the capacitor being determined in order to achieve impedance matching of the first antenna with the radio frequency circuit.

11. The multi-band antenna according to claim 1 , wherein the first feed element, the second feed element and the third feed element are connected to a feed port.

12. The multi-band antenna according to claim 11 , wherein the second feed element is connected to the third feed element by a first microstrip line printed in the second conductive layer and at least one through connector, said first microstrip line being arranged below or above the third radiating element, and the first feed element is connected to the third feed element by a second microstrip line printed in the third conductive layer and at least one through connector, said second microstrip line being arranged below or above the first radiating element.

13. The multi-band antenna according to claim 1 , wherein one of said first and second conductive layers further comprises a third radiating element, a third feed element connected to said third radiating element and a third ground return element connected to said third radiating element and said ground section, the length of the third radiating element being different from the lengths of said first and second radiating elements, said third radiating element and said third feed element being offset transversally from said first and second radiating elements, said first and second feed elements and said ground section,
said third radiating element, said third feed element and said third ground return element being arranged to form a third F antenna resonating in a third frequency band.

14. The multi-band antenna according to claim 1 wherein the first antenna, the second antenna and/or the third antenna is formed as an inverted F antenna.

15. The multi-band antenna according to claim 1 wherein at least part of the first feed element, the second feed element and/or the link includes one or more electronic components.

16. An electronic device for wireless communication comprising a multi-band antenna according to claim 1 .

Assignees

• Thomson Licensing

Inventors

• Lo Hine Tong Dominique
• Minard Philippe
• Robert Jean-Luc

Classifications

• H01Q9/0421 Primary

  with a shorting wall or a shorting pin at one end of the element (H01Q9/0414 takes precedence) · CPC title

• H01Q1/48

  Earthing means; Earth screens; Counterpoises · CPC title

• H01Q9/42

  with folded element, the folded parts being spaced apart a small fraction of the operating wavelength · CPC title

• H01Q21/30

  Combinations of separate antenna units operating in different wavebands and connected to a common feeder system · CPC title

• H01Q5/40

  Imbricated or interleaved structures; Combined or electromagnetically coupled arrangements, e.g. comprising two or more non-connected fed radiating elements · CPC title