Antenna diversity arrangement

• US 20040014432A1
• Filed: 03/21/2001
• Published: 01/22/2004
• Est. Priority Date: 03/23/2000
• Status: Active Grant

• Current Assignee: Breakwaters Innovations LLC
• Original Assignee: US Philips Corporation (Koninklijke Philips N.V.)
• Inventors: Boyle, Kevin R.
• Granted Patent: US 6,807,401 B2
• Time in Patent Office: Days
• US Class Current: 455/101
• CPC Class Codes: H01Q 1/241 used in mobile communications, e.g. GSM H01Q1/247, H01Q1/248 take precedence
• CPC Class Codes: H01Q 25/00 Antennas or antenna systems providing at least two radiating patterns arrangements for changing or varying the orientation or the shape of the directional pattern H01Q3/00
• CPC Class Codes: H04B 7/0617 for beam forming

Abstract

An antenna diversity arrangement (200) comprises a plurality of antennas (204a, 204b) capable of forming a plurality of antenna beams. The amplitude and phase relationships between the signals driving each of the antennas (204a, 204b) are first determined for an arrangement where each antenna is replaced by a point source. The results of this analysis are then transformed by reference to the characteristics of the real antenna arrangement (200) to determine appropriate driving signals.

The resultant antenna diversity arrangements (200) can have antennas (204a, 204b) located arbitrarily close to one another with near-zero correlation between any pair of the antenna beams, thereby providing a compact and effective arrangement.

Claims

1. An antenna diversity arrangement comprising a plurality of antennas and means for feeding each of the plurality of antennas with a signal of suitable amplitude and phase to enable the generation of a plurality of antenna beams, wherein the correlation coefficient between any pair of beams is substantially zero.

2. An arrangement as claimed in claim 1, characterised in that the amplitude and phase of the signal feeding each antenna is predetermined.

3. An arrangement as claimed in claim 1 or 2, characterised in that the amplitudes of all the feed signals are substantially equal.

4. An arrangement as claimed in claims 1 or 2, characterised in that the diversity arrangement comprises two antennas.

5. An arrangement as claimed in claim 4, characterised in that the phase difference between the feed signals of an equivalent point source antenna diversity arrangement is substantially equal to cos⁻

1(−

J₀(kd)), where kd is the electrical spacing of the antennas.

6. A wireless device incorporating an antenna diversity arrangement as claimed in claim 1 or 2.

7. A wireless device incorporating an antenna diversity arrangement as claimed in claim 3.

8. A wireless device incorporating an antenna diversity arrangement as claimed in claim 4.

9. A wireless device incorporating an antenna diversity arrangement as claimed in claim 5.

10. A method of operating an antenna diversity arrangement comprising a plurality of antennas, the method comprising feeding each of the plurality of antennas with a signal of suitable amplitude and phase to enable the generation of a plurality of antenna beams, wherein the correlation coefficient between any pair of beams is substantially zero.

11. A method as claimed in claim 10, characterised by the amplitude and phase of the signal feeding each antenna being predetermined.

12. A method as claimed in claim 10 or 11, characterised by the amplitudes of all the feed signals being substantially equal.

13. A method as claimed in claims 10 or 11, characterised by the diversity arrangement comprising two antennas and by the phase difference between the feed signals of an equivalent point source antenna diversity arrangement being substantially equal to cos⁻

1(−

J₀(kd)), where kd is the electrical spacing of the antennas.