Antenna arrangement

• US 6,140,974 A
• Filed: 10/20/1998
• Issued: 10/31/2000
• Est. Priority Date: 10/20/1998
• Status: Expired due to Term

• Current Assignee: Apple Inc.
• Original Assignee: Nortel Networks Limited (Nortel Networks Corporation)
• Inventors: Dalley, James Edward
• Primary Examiner(s): LE, HOANGANH T
• Application Number:
  US09/175,879
• Time in Patent Office: 742 Days
• Field of Search: 343/806, 343/833, 343/834, 343/835, 343/836, 343/829, 343/846, 343/848, 343/803, 343/810
• US Class Current: 343/806
• 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 3/2617 Array of identical elements
• CPC Class Codes: H01Q 9/26 with folded element or elements, the folded parts being spaced apart a small fraction of operating wavelength resonant loop antennas H01Q7/00

Abstract

The present invention provides an auxiliary or side lobe cancelling antenna particularly for horizontally polarised main antennas. The auxiliary antenna arrangement for cancelling side lobe interference from a main antenna comprises a ground plane shaped in a concertina or zig-zag fashion. Dipole pairs are spaced from and arranged perpendicular to the front bends, the dipoles having ends angled towards corresponding ground plane sections. The dipoles are connected anti-phase to provide a radiation pattern approximating an ideal auxiliary antenna mask of the main antennas pattern.

Claims

1. An antenna arrangement comprising:

a pair of substantially co-planar dipoles each spaced from a folded ground plane comprising two forward bends, each bend being normal to said folded ground plane of said dipole pair and adjacent the centre of one of the dipoles; and

wherein the ends of each dipole are arranged substantially parallel to a corresponding section of the ground plane.

2. An antenna arrangement as claimed in claim 1 further comprising one or more additional pairs of co-planar dipoles, wherein each dipole of said additional pair is substantially parallel with a corresponding dipole of said first pair, the ends of each additional dipole being arranged substantially parallel to a corresponding section of the ground plane.

3. An antenna arrangement as claimed in claim 1 further comprising one or more additional dipoles co-planar with said first dipole pair, the additional dipoles being spaced from a forward bend of the ground plane, each bend being normal to said plane and adjacent the centre of a corresponding additional dipole;

and wherein the ends of each additional dipole are arranged substantially parallel to a corresponding section of the ground plane.

4. An antenna arrangement as claimed in claim 1, wherein the antenna arrangement is an auxiliary antenna.

5. A method of operating an antenna arrangement comprising a pair of substantially co-planar dipoles each spaced from a folded ground plane comprising two forward bends, each bend being normal to said folded ground plane of said dipole pair and adjacent the centre of one of the dipoles;

and wherein the ends of each dipole are arranged substantially parallel to a corresponding section of the ground plane [section];

the method comprising the steps of;

operating the dipoles out of phase with respect to each other; and

subtracting the signals received from said antenna arrangement from those received from a main antenna.

6. A method as claimed in claim 5, wherein said dipoles are operated substantially 180°

out of phase such that said antenna arrangement operates as an auxiliary antenna.

7. A method as claimed in claim 5, wherein said dipoles are operated less than 180°

out of phase such that the forward gain of said antenna arrangement is dependent on the amount of phase difference between the dipoles.