GPS antenna with jamming signal shielding

摘要

An antenna apparatus comprises an antenna cover 120 which includes a shielding unit 110 formed on a predetermined portion of one hemispherical surface of the antenna cover. The shielding unit 110 may be formed of electromagnetic shielding material which may reflect or absorb a jamming signal. The shielding 110 may cover a range of low angle signal reception directions relative to the antenna. The shielding 110 may be in the form of a paint applied to a surface of an antenna cover. The shielding 110 may be controlled to block certain signal directions. The shielding material may be formed on or adjacent the surface of a hemispherical, electromagnetic transparent radome. The shielding may be arranged to be rotated in a vertical and/or horizontal manner to block one or more jamming signals. Also disclosed is a method for shielding an antenna, comprising: detecting if a jamming signal is present. If a jamming signal is detected, then the shielding is rotated until the jamming signal is at a receive sensitivity or less. If no jamming signal is detected then the position of the shielding is controlled such that the shielding is located in a north direction relative to the antenna. The apparatus and method provides a simple and cheap way of avoiding jamming signals.