05986615 is referenced by 41 patents and cites 14 patents.

An antenna structure has a radiating element and a ground plane. The ground plane has a central region relatively closely spaced apart from the radiating element and a peripheral region extending away from the central region. The peripheral region comprises at least the conductive layer that extends radially beyond the radiating element and provides a sheet resistivity higher than that of the radiating element. Though physically small, the ground plane simulates an infinite ground plane, and the antenna structure reduces multipath signals caused by reflection from the earth.

Title
Antenna with ground plane having cutouts
Application Number
8/934146
Publication Number
5986615
Application Date
September 19, 1997
Publication Date
November 16, 1999
Inventor
Kevin B Stephenson
Mountain View
CA, US
Brian G Westfall
Modesto
CA, US
Agent
Donald S Cooper & Dunham Dowden
Assignee
Trimble Navigation
CA, US
IPC
H01Q 1/48
View Original Source