Impedance-controlled dual-feed antenna

Patent metadata

Field	Value
Publication number	US-9711858-B1
Application number	US-201313781279-A
Country	US
Kind code	B1
Filing date	Feb 28, 2013
Priority date	Feb 28, 2013
Publication date	Jul 18, 2017
Grant date	Jul 18, 2017

Abstract

Antenna structures and methods of operating the same of a dual-feed antenna of an electronic device are described. A dual-feed antenna includes a first antenna element coupled to a controllable circuit that is coupled a first radio frequency (RF) feed, and a second antenna element coupled to a second RF feed. The controllable circuit is configured to electrically connect the first antenna element to the first RF feed in a first antenna configuration and to electrically connect the first antenna element to ground in a second antenna configuration. During the second antenna configuration, the second antenna element is driven by the second RF feed.

First claim

What is claimed is:

1. An electronic device, comprising:
a first tunable radio frequency (RF) feed;
a folded monopole structure coupled to the first tunable RF feed at a first end and to a ground plane at a second end of the folded monopole structure;
a second RF feed; and
a coupled monopole structure, a first end of which is coupled to the second RF feed and a second end of which is coupled to the ground plane, wherein the folded monopole structure and the coupled monopole structure are located within a plane parallel to the ground plane, and wherein the first tunable RF feed is to:
in a first mode, feed the folded monopole structure to operate as a radiating element in a low band; and
in a second mode, electrically short the first end of the folded monopole structure to the ground plane such that the folded monopole structure acts as a parasitic element in a high band, the parasitic element being parasitically coupled to the coupled monopole structure while the coupled monopole structure is fed in the high band.

2. The electronic device of claim 1 , further comprising a parasitic ground element coupled to the ground plane and parasitically coupled to the coupled monopole structure, wherein the parasitic ground element is not conductively connected to the second RF feed.

3. The electronic device of claim 1 , wherein the folded monopole structure is to radiate electromagnetic energy as a folded monopole antenna in the first mode and to radiate electromagnetic energy as a parasitic ground element in the second mode when the first tunable RF feed electrically shorts the folded monopole structure to the ground plane.

4. The electronic device of claim 3 , wherein the folded monopole antenna is to operate in a first frequency range of about 700 MHz to about 960 MHz in the first mode and the parasitic ground element is to operate in a second frequency range of about 1.71 GHz to about 2.69 GHz in the second mode.

5. The electronic device of claim 1 , further comprising a controllable circuit coupled to the first tunable RF feed, wherein the controllable circuit comprises:
a switch;
a first matching network coupled to the first RF feed; and
a second matching network coupled to the ground plane, wherein the switch is to couple the folded monopole structure to the first matching network in a first antenna configuration and to couple the folded monopole structure to the second matching network in a second antenna configuration.

6. An apparatus comprising:
a first radio frequency (RF) feed;
a controllable circuit coupled to the first RF feed;
a second RF feed; and
an antenna structure comprising:
a first antenna element coupled to the controllable circuit; and
a second antenna element coupled to the second RF feed,
wherein the second antenna element includes a coupled monopole structure coupled between the second RF feed and a ground, and
wherein the controllable circuit is to electrically connect the first antenna element to the first RF feed in a first antenna configuration to operate as a low-band radiating element and to electrically connect the first antenna element to the ground in a second antenna configuration to operate as a high-band radiating element.

7. The apparatus of claim 6 , wherein the first antenna element is a folded monopole structure in the first antenna configuration and a parasitic ground element in the second antenna configuration.

8. The apparatus of claim 6 , wherein the first antenna element is a loop antenna structure in the first antenna configuration and a parasitic ground element in the second antenna configuration.

9. The apparatus of claim 6 , wherein the first antenna element is a patch antenna structure in the first antenna configuration and a parasitic ground element in the second antenna configuration.

10. The apparatus of claim 9 , wherein the patch antenna structure is a planar inverted-F antenna (PIFA) structure.

11. The apparatus of claim 6 , wherein the controllable circuit comprises:
a switch;
a first matching network coupled to the first RF feed; and
a second matching network coupled to the ground, wherein the switch is to couple the first antenna element to the first matching network in the first antenna configuration and to couple the first antenna element to the second matching network in the second antenna configuration.

12. The apparatus of claim 6 , wherein the antenna structure is to operate in a first frequency range in the first antenna configuration and the antenna structure is to operate in a second frequency range in the second antenna configuration, wherein the first frequency range is about 700 MHz to about 960 MHz and the second frequency range is about 1.71 GHz to about 2.69 GHz.

13. The apparatus of claim 6 , wherein the first antenna element is to operate in a first frequency range of about 700 MHz to about 960 MHz in the first antenna configuration and the first antenna element is to operate in a second frequency range of about 2.1 GHz to about 2.69 GHz in the second antenna configuration.

14. The apparatus of claim 6 , wherein the first antenna element comprises a folded monopole structure, wherein the folded monopole structure further comprises:
a first portion that extends from the first RF feed in a first direction until a first fold;
a second portion that extends from the first fold in a second direction until a second fold;
a third portion that extends from the second fold in a third direction until a third fold;
a fourth portion that extends from the third fold in a fourth direction until a fourth fold and is laid out at least partially in parallel to the second portion; and
a fifth portion that extends from the fourth fold in a fifth direction until the ground and is laid out at least partially in parallel to the first portion, and wherein the controllable circuit is disposed at a proximal end of the first portion, the proximal end being the nearest from the first RF feed.

15. The apparatus of claim 14 , wherein a section of a distal end of the folded monopole structure is folded in the third direction towards the ground.

16. The apparatus of claim 14 , further comprising a parasitic ground element coupled to the ground, wherein the parasitic ground element is not conductively connected to the second RF feed.

17. The apparatus of claim 16 , wherein the second antenna element comprises:
a sixth portion that extends from the second RF feed in the first direction until a fifth fold and is laid out at least partially in parallel to the first portion;
a seventh portion that extends from the fifth fold in the fourth direction until a sixth fold; and
an eighth portion that extends from the sixth fold in the third direction, wherein a gap is between a distal end of the eighth portion and the ground, the distal end being the farthest from the second RF feed.

18. The apparatus of claim 17 , wherein the parasitic ground element comprises:
a ninth portion that extends from the ground in the first direction until a seventh fold;
a tenth portion that extends from the seventh fold in the fourth direction until an eighth fold;
an eleventh portion that extends from the eighth fold in the first direction until a ninth fold; and
a block portion coupled to a distal end of the ninth portion, the distal end being the farthest away from the ground, wherein the block portion extends in at least one of the second direction or fourth direction and is laid out at least partially in parallel to the seventh portion.

19. The apparatus of claim 6 , further comprisi

Assignees

• Amazon Tech Inc

Inventors

• Lee Tzung-I
• Hyun In Chul
• Kim Cheol Su

Classifications

• H01Q5/378

  Combination of fed elements with parasitic elements · CPC title

• H01Q1/36

  Structural form of radiating elements, e.g. cone, spiral, umbrella; {Particular materials used therewith}(H01Q1/08, H01Q1/14 take precedence) · CPC title

• H01Q9/06 Primary

  Details · CPC title

• H01Q9/42 Primary

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

• H01Q5/335

  at the feed, e.g. for impedance matching · CPC title