Compact single-aperture antenna and navigation system

• Main Authors: WERNER BENJAMIN D, EZAL KENAN O, MUJAHED TARIQ A
• Format: Patent
• Language: English
• Published: 11.12.2008
• Subjects: ANALOGOUS ARRANGEMENTS USING OTHER WAVES; ANTENNAS, i.e. RADIO AERIALS; BASIC ELECTRIC ELEMENTS; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; ELECTRICITY; GYROSCOPIC INSTRUMENTS; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION ORRERADIATION OF RADIO WAVES; MEASURING; MEASURING DISTANCES, LEVELS OR BEARINGS; NAVIGATION; PHOTOGRAMMETRY OR VIDEOGRAMMETRY; PHYSICS; RADIO DIRECTION-FINDING; RADIO NAVIGATION; SURVEYING; TESTING

An exemplary radio-based navigation system uses a single-aperture multimode direction-finding antenna capable of determining platform position, velocity, attitude, and time while simultaneously providing protection against narrowband and broadband sources of interference. Global Navigation Satellite System (GNSS)-signals such as those from the Global Positioning System (GPS) provide protection against jammers while simultaneously providing attitude measurements with a compact single-aperture multimode antenna (e.g., a small two-arm spiral with improved angle-of-arrival performance over the entire hemisphere enhanced through the use of a conductive vertical extension of the antenna ground plane about the antenna perimeter and/or conductive posts placed evenly around the antenna perimeter). The multimode spiral may be treated as an array of cylindrically symmetric antenna elements. GPS receiver correlation architecture also may be modified for attitude determination by increasing the requisite number of input signals from one to at least two while minimizing the required number of correlators and mixers.