Space saving multiband antenna

• US 9,608,329 B2
• Filed: 11/08/2013
• Issued: 03/28/2017
• Est. Priority Date: 11/08/2012
• Status: Active Grant

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Inventors: Liu, Luyi, Iellici, Devis
• Primary Examiner(s): PHAN, THO GIA
• Application Number:
  US14/440,561
• Publication Number:
  US 20150280323A1
• Time in Patent Office: 1,236 Days
• Field of Search: 343/700.MS, 343/702, 343/829, 343/846
• US Class Current: 1/1
• CPC Class Codes: H01Q 1/243 with built-in antennas
• CPC Class Codes: H01Q 5/307 Individual or coupled radiating elements, each element being fed in an unspecified way
• CPC Class Codes: H01Q 5/328 between a radiating element and ground
• CPC Class Codes: H01Q 5/335 at the feed, e.g. for impedance matching
• CPC Class Codes: H01Q 5/357 using a single feed point
• CPC Class Codes: H01Q 9/0414 in a stacked or folded configuration
• CPC Class Codes: H01Q 9/0421 with a shorting wall or a shorting pin at one end of the element H01Q9/0414 takes precedence
• CPC Class Codes: H01Q 9/42 with folded element, the folded parts being spaced apart a small fraction of the operating wavelength
• CPC Class Codes: H04B 7/02 Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas RAKE receivers H04B1/7115

Abstract

There is disclosed a multiband antenna device comprising a conductive elongated antenna element configured for electrical connection to a conductive groundplane at a grounding point, and for electrical connection to a radio transmitter/receiver at a feeding point. The antenna element comprises a first portion and a second portion. The first portion is configured to extend in a first direction along a first outside edge of the groundplane, and then in a second direction along a second outside edge of the groundplane. The second portion of the antenna element is configured to double back next to the first portion in a third, substantially counter-parallel direction back along the second outside edge of the groundplane, and then in a fourth direction along the first outside edge of the groundplane. The second portion of the antenna element terminates with a high impedance portion, and the high impedance portion of the antenna element is positioned between the first edge of the ground plane and the first portion of the antenna element so as to form a narrow gap that electromagnetically couples the first and second portions of the antenna element.

Claims

1. A multiband antenna device comprising a conductive elongate antenna element configured for electrical connection to a conductive groundplane at a grounding point, and for electrical connection to a radio transmitter/receiver at a feeding point, wherein the antenna element comprises a first portion and a second portion, the first portion is configured to extend in a first direction along a first outside edge of the groundplane, and then in a second direction along a second outside edge of the groundplane, and the second portion of the antenna element is configured to double back next to the first portion in a third, substantially counter-parallel direction back along the second outside edge of the groundplane, and then in a fourth direction along the first outside edge of the groundplane, the second portion of the antenna element terminating with a high impedance portion, the high impedance portion of the antenna element being positioned between the first edge of the ground plane and the first portion of the antenna element, and forming a narrow gap that electromagnetically couples the first and second portions of the antenna element.

2. The device of claim 1, wherein the antenna element extends in two planes, each plane substantially orthogonal to the groundplane.

3. The device of claim 2, wherein the two planes are substantially orthogonal to each other.

4. The device of claim 1, wherein the antenna element is configured to fit about or conform to a corner of the groundplane.

5. The device of claim 1, wherein the grounding point and the feeding point are adjacent to each other and provide a shunt inductance near the feeding point which compensates the capacitive behaviour of the antenna and creates an approximate resonance in the antenna impedance.

6. The device of claim 1, wherein an impedance matching circuit is interposed between the feeding point of the antenna element and the radio transmitter/receiver.

7. The device of claim 1, wherein the antenna element is positioned within an area defined by the groundplane, and a portion of the conductive part of the groundplane is removed directly underneath the antenna element.

8. The device of claim 1, wherein the antenna element is provided with an antenna extension comprising an additional portion extending from the antenna element in a third plane substantially parallel to the groundplane so as to increase the effective electrical length of the antenna element.

9. The device of claim 1, wherein the antenna element is connected to the groundplane through an impedance element such as an inductor or a capacitor.

10. The device of claim 9, wherein the impedance element is an electronically controlled variable impedance.