ANTI-JAMMING AND REDUCED INTERFERENCE GLOBAL POSITIONING SYSTEM RECEIVER METHODS AND DEVICES

摘要

Global navigation satellite system (GNSS) radio frequency signals broadcastfromgeo-stationary satellites 20,000 km above the earth when received by GNSSreceivers arefundamentally weak. Accordingly, these GNSS receivers are vulnerable toaccidental anddeliberate interference from a range of manmade sources as well as naturalsources. Existinganti-jamming technologies such as controlled reception pattern antennas,adaptive antennas,null-steering antennas, and beamforming antennas etc. are expensive andincompatible withmany lower cost and footprint limited applications. However, in manyapplications the GNSSantenna is mounted upon a fixed or mobile element such that accidental andintentionaljammers tend to be in the plane of the antenna or below it. Accordingly, thereare presenteddesigns and techniques to improve the anti-jamming or interference performanceof GNSSreceivers by further reducing the responsivity of the GNSS receiver to signalsin-plane or belowthe plane of the antenna.