UNIDIRECTIONAL ANTENNA COMPRISING A DIPOLE AND A LOOP

• US 20100103061A1
• Filed: 10/23/2008
• Published: 04/29/2010
• Est. Priority Date: 10/23/2008
• Status: Active Grant

• Current Assignee: City University of Hong Kong
• Original Assignee: City University of Hong Kong
• Inventors: YUNG, Edward Kai Ning, WONG, Hang, CHAN, Pak Wai
• Granted Patent: US 8,410,982 B2
• Time in Patent Office: Days
• US Class Current: 343/730
• CPC Class Codes: H01Q 21/29 Combinations of different interacting antenna units for giving a desired directional characteristic H01Q25/00 takes precedence
• CPC Class Codes: H01Q 7/00 Loop antennas with a substantially uniform current distribution around the loop and having a directional radiation pattern in a plane perpendicular to the plane of the loop
• CPC Class Codes: H01Q 9/28 Conical, cylindrical, cage, strip, gauze, or like elements having an extended radiating surface; Elements comprising two conical surfaces having collinear axes and adjacent apices and fed by two-conductor transmission lines waveguide horns or mouths H01Q13/00; slot antennas H01Q13/00

Abstract

A unidirectional wireless antenna with a front-to-back ratio of 20 dB comprises a loop antenna and a dipole antenna interconnected by a metallic element and printed on a printed circuit board. The antenna is small in size but provides good unidirectional transmission.

Claims

1. A unidirectional antenna for at least one of transmitting and receiving radio frequency waves, the unidirectional antenna comprising a dipole antenna and a loop antenna connected by a metallic connecting element, wherein the dipole antenna, loop antenna and metallic connecting element are formed on a substrate.

2. The antenna of claim 1, wherein the unidirectional antenna generates a unidirectional radiation pattern with front-to-back ratio of 20 dB.

3. The antenna of claim 1, wherein the dipole antenna is a fat dipole.

4. The antenna of claim 1, wherein the loop antenna is a rectangular loop antenna.

5. The antenna of claim 1, wherein the loop antenna has a shape that is one of circular and square.

6. The antenna of claim 1, wherein no ground plane is provided.

7. The antenna of claim 1, wherein the substrate comprises a printed circuit board.

8. The antenna of claim 1, wherein one end of the loop antenna is connected to a SubMiniature version A (SMA) connector and the other end of the loop antenna is connected to ground.

9. The antenna of claim 1, wherein the unidirectional antenna is fed without a balun.

10. A unidirectional antenna for at least one of transmitting and receiving radio frequency waves, the unidirectional antenna comprising a dipole antenna and a loop antenna coupled by a metallic element, wherein the dipole antenna, loop antenna and metallic element are formed on a substrate.