Ultra isolation antenna

• US 7,868,837 B2
• Filed: 12/21/2005
• Issued: 01/11/2011
• Est. Priority Date: 12/21/2004
• Status: Expired due to Fees

• Current Assignee: Electronics and Telecommunications Research Institute
• Original Assignee: Electronics and Telecommunications Research Institute
• Inventors: Lim, Jong-sik, Moon, Jung-ick, Yun, Je-hoon, Kim, Chang-joo
• Primary Examiner(s): Mancuso; Huedung
• Application Number:
  US11/722,272
• Publication Number:
  US 20090267849A1
• Time in Patent Office: 1,847 Days
• Field of Search: 343/727, 343/841, 343/895, 343/844, 343/846
• US Class Current: 343/727
• CPC Class Codes: H01Q 1/521 reducing the coupling between adjacent antennas
• CPC Class Codes: H01Q 1/526 Electromagnetic shields
• CPC Class Codes: H01Q 21/28 Combinations of substantially independent non-interacting antenna units or systems multiple beam H01Q25/00
• CPC Class Codes: H01Q 25/005 providing two patterns of opposite direction; back to back antennas H01Q25/004 takes precedence
• CPC Class Codes: H01Q 25/02 providing sum and difference patterns H01Q25/04 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 9/32 Vertical arrangement of element H01Q9/40 takes precedence

Abstract

Provided is a transmitting/receiving isolation antenna that can perform wireless bi-directional communication in the co-channel, co-polarization and co-time by acquiring high isolation from transmitting and receiving antennas having co-time, co-channel and co-polarization and set up adjacently. The isolation antenna includes a first antenna; second and third antennas symmetrically positioned in the same distance from the first antenna; a shielding unit symmetrically positioned between the first and second antennas, and between the first and third antennas; and a signal removing unit for removing a signal transmitted from the first antenna to the second and third antennas.

Claims

1. A transmitting/receiving ultra isolation antenna for maintaining high isolation between a transmitting signal and a receiving signal, comprising:

a shielding box having a vacant space inside;

a first antenna mounted onto the shielding box;

a second and a third antennas mounted onto the shielding box which are symmetrically positioned in a same distance from the first antenna;

a shielding means mounted onto the shielding box symmetrically positioned between the first and second antennas and between the first and third antennas; and

a reflection signal removing means for removing a signal transmitted to the second and third antennas from the first antenna.

2. The ultra isolation antenna as recited in claim 1, wherein the shielding box is positioned in a lower part of the first antenna, the second antenna, the third antenna, and the shielding means and having a structure covered by electric conductor entirely and has coaxial cable connectors mounted onto the shielding box within the vacant space inside such that the coaxial cable connectors are coupled to the first, second and third antennas.

3. The ultra isolation antenna as recited in claim 1, wherein the shielding means has a wall structure of an electric conductor.

4. The ultra isolation antenna as recited in claim 1, wherein the reflection signal removing means is connected to the second and third antennas with a cable of a same length.

5. The ultra isolation antenna as recited in claim 2, wherein the reflection signal removing means removes radiation signal from the first antenna by using power difference with respect to an input terminal of the second and third antennas.

6. The ultra isolation antenna as recited in claim 1, wherein a direction of a feeding means of the second and third antennas is perpendicular to a direction of a feeding means of the first antenna to increase isolation.

7. The ultra isolation antenna as recited in claim 1, wherein the second and third antennas are directional antennas and a main beam of the second antenna is in an opposite direction from a main beam of the third antenna.

8. The ultra isolation antenna as recited in claim 1, wherein the second and third antennas have a same shape and are formed of a same material.

9. The ultra isolation antenna as recited in claim 2, wherein the reflection signal removing means removes a signal from the first antenna based on power summation with respect to input terminals of the second and third antennas.

10. The ultra isolation antenna as recited in claim 9, wherein the feeding means of the second and third antennas are in opposite direction each other.

11. The ultra isolation antenna as recited in claims 1, wherein the first antenna is a monopole antenna, and the second and third antennas are loop antennas.

12. The ultra isolation antenna as recited in claims 1, wherein the first to third antennas are monopole antennas.

13. The ultra isolation antenna as recited in claims 1, wherein the first to third antennas use any one among a loop antenna, a monopole antenna, a dipole antenna, a horn antenna, a double ridged horn antenna and a reflector antenna.

14. The ultra isolation antenna as recited in claims 1, wherein the first antenna to third antennas use any one among a square, a circular and spherical ultra broadband antennas.

15. A transmitting/receiving ultra isolation antenna for maintaining high isolation between a transmitting signal and a receiving signal, comprising:

a first antenna mounted onto the shielding box;

a second and a third antenna mounted onto the shielding box which are symmetrically positioned in a same distance from the first antenna;

the shielding box having a vacant space inside which is positioned in a lower part of the first antenna, the second antenna and the third antenna and has a structure covered by electric conductor; and

a reflection signal removing means for removing a signal transmitted from the first antenna to the second and third antennas.

16. The ultra isolation antenna as recited in claim 15, wherein the shielding box has a symmetrical structure that a central part where the first antenna is positioned is higher than left and right parts where the second and third antennas are positioned.