Multiple-input multiple-output (MIMO) antennas with multi-band wave traps

Patent metadata

Field	Value
Publication number	US-9379433-B2
Application number	US-201213697943-A
Country	US
Kind code	B2
Filing date	Jan 5, 2012
Priority date	Oct 31, 2011
Publication date	Jun 28, 2016
Grant date	Jun 28, 2016

Abstract

An antenna includes a first radiating element, a second radiating element, a common ground plane between the first radiating element and the second radiating element, and a wavetrap structure coupled to the ground plane and configured to reduce correlation between the first and second radiating elements at first and second RF frequencies.

First claim

What is claimed is:

1. An antenna comprising:
a first radiating element;
a second radiating element;
a common ground plane between the first radiating element and the second radiating element; and
a wavetrap structure coupled to the ground plane and configured to reduce correlation between the first and second radiating elements at first and second RF frequencies;
wherein the wavetrap structure comprises:
a first ground post connected to the ground plane;
a second ground post connected to the ground plane;
a first conductive strip coupled to the first ground post and having an electrical length that is one quarter of a wavelength of the first RF frequency; and
a second conductive strip coupled to the second ground post and having an electrical length that is one quarter of a wavelength of the second RF frequency;
wherein the ground plane has a first end and a second end opposite the first end;
the first radiating element is adjacent the first end of the ground plane and the second radiating element is adjacent the second end of the ground plane;
the first and second ground posts are proximate the first end of the ground plane;
the first conductive strip extends away from the first ground post toward the second end of the ground plane; and
the second conductive strip extends away from the second ground post toward the second end of the ground plane; and
the ground plane has a first side and a second side opposite the first side;
the antenna further comprising:
a first feed element coupled to the first radiating element at a first end of the first radiating element proximate the first side of the ground plane; and
a second feed element coupled to the second radiating element at a first end of the second radiating element proximate the first side of the ground plane;
the first ground post and the second ground post are proximate the second side of the ground plane;
the first conductive strip extends from the first ground post toward an open end of the second radiating element opposite the first end of the second radiating element; and
the second conductive strip extends from the second ground post toward the open end of the second radiating element.

2. The antenna of claim 1 , further comprising a capacitive element between an open end of the first conductive strip opposite the ground post and the ground plane.

3. The antenna of claim 1 , wherein the ground post comprises an inductive element.

4. The antenna of claim 3 , further comprising a capacitive element between an open end of the first conductive strip opposite the ground post and the ground plane.

5. The antenna of claim 1 , wherein the first and second radiating elements have an envelope correlation coefficient less than 0.5 for a first frequency in the first RF frequency range and for a second frequency in the second RF frequency range.

6. The antenna of claim 1 , wherein the wavetrap structure comprises: a ground post connected to the ground plane; and a patch structure coupled to the ground post and configured to resonate at the first RF frequency.

7. The antenna of claim 1 , wherein the wavetrap structure comprises: a ground post connected to the ground plane; and a spiral structure coupled to the ground post and configured to resonate at the first RF frequency.

8. A wireless terminal, comprising:
a transceiver; and
an antenna coupled to the transceiver, the antenna comprising:
a first radiating element;
a second radiating element;
a common ground plane between the first radiating element and the second radiating element; and
a wavetrap structure coupled to the ground plane and configured to reduce correlation between the first and second radiating elements at first and second RF frequencies;
wherein the wavetrap structure comprises:
a first ground post connected to the ground plane;
a second ground post connected to the ground plane;
a first conductive strip coupled to the first ground post and having an electrical length that is one quarter of a wavelength of the first RF frequency; and a second conductive strip coupled to the second ground post and having an electrical length that is one quarter of a wavelength of the second RF frequency;
wherein:
the ground plane has a first end and a second end opposite the first end;
the first radiating element is adjacent the first end of the ground plane and the second radiating element is adjacent the second end of the ground plane;
the first ground post is proximate the second end of the ground plane;
the second ground post is proximate the first end of the ground plane;
the first conductive strip extends away from the first ground post toward the first end of the ground plane; and
the second conductive strip extends away from the second ground post toward the second end of the ground plane;
wherein the ground plane has a first side and a second side opposite the first side; the antenna further comprising:
a first feed element coupled to the first radiating element at a first end of the first radiating element proximate the first side of the ground plane; and
a second feed element coupled to the second radiating element at a first end of the second radiating element proximate the second side of the ground plane;
the first ground post is proximate the second side of the ground plane;
the second ground post is proximate the first side of the ground plane;
the first conductive strip extends from the first ground post toward a second end of the first radiating element opposite the first end of the first radiating element; and
the second conductive strip extends from the second ground post toward a second end of the second radiating element opposite the first end of the second radiating element.

9. The wireless terminal of claim 8 , further comprising a housing, wherein the ground plane is disposed within the housing and wherein the wavetrap structure is provided on an outer surface of the housing.

Assignees

• Ying Zhinong
• Sony Corp
• Sony Mobile Comm Inc

Inventors

• Ying Zhinong

Classifications

• H01Q1/48 Primary

  Earthing means; Earth screens; Counterpoises · CPC title

• H01Q1/521

  reducing the coupling between adjacent antennas · CPC title

• H01Q1/243

  with built-in antennas · CPC title

• H01Q1/523 Primary

  between antennas of an array · CPC title

• H01Q21/28

  Combinations of substantially independent non-interacting antenna units or systems {(multiple beam H01Q25/00)} · CPC title