Patent Number: 6,311,075

Title: Antenna and antenna operation method for a cellular radio communications system

Abstract: A conventional antenna 114 at a cell site of a sectored cell in a cellular radio communications system has a low angle of coverage in elevation and therefore has low gain for close-in subscriber units (near the cell site). In a sectored cell, a main beam antenna in a first sector generates sidelobes and backlobes which may fall within the close-in area in other sectors. A close-in mobile in one of the other sectors may move into such an out-of-sector lobe and cause unexpected interference to the base station transceiver (BTS) of the first sector. A downward-looking antenna (DIA) 110 supplements the conventional antenna in each sector and has a beam 112 covering the close-in area. The gain of the DLA beam is greater than that of any out-of-sector lobes and so provides a subscriber unit with a higher gain link to the BTS of its own sector than is provided by out-of-sector lobes to the BTS of any other sector.

Inventors: Bevan; David Damian Nicholas (Bishops Stortford, GB), Baines; Steven John (Stansted Mountfichet, GB)

Assignee: Northern Telecom Limited

International Classification: H01Q 1/24 (20060101); H01Q 21/29 (20060101); H01Q 21/00 (20060101); H04B 001/38 ()

Expiration Date: 10/30/2018