Navxation's patented Accutenna® technology is employed in many of our antennas. Independent, side-by-side tests employing GPS(L1) and GLONASS(G1) signals have shown that Accutenna® technology out performs single feed patch antennas. Accutenna® technology provides superior multi-path signal rejection thereby providing un-matched precision for its size and price.
Key Accutenna® technology features
- Employs Navxation's unique dual feed ceramic patch technology
- Provides truly circular response over the entire antenna bandwidth of approximately 80 MHz
- Provides superior rejection of cross polarized signals (multi-path)
- Offers pre-filtering option to provide additional protection from near band signals
- Single patch Accutenna® technology antennas provide wide band coverage of the upper GNSS band, supporting multi-constellational coverage: GPS (L1), GLONASS (G1), Galileo (E1), BeiDou (B1) and L-Band Correction services
- Dual patch Accutenna® technology antennas provide wide band coverage of the upper and lower GNSS band, supporting multi-constellational and multi-frequency coverage: GPS (L1/L2/L5), GLONASS (G1/G2/G3), Galileo (E1/E5) and BeiDou (B1/B2)
GNSS has changed. An increasing number of GNSS receivers can track several constellations (GPS/GLONASS/Galileo/BeiDou) and many frequencies. Single feed antennas were suitable for single constellation and single frequency tracking. In today's multi GNSS environment, Navxation's Accutenna® technology is required to provide the accuracy and precision supported by Real-Time Kinematic (RTK) and Precise Point Positioning (PPP) applications.
What is a Dual Feed Antenna?
Dual feed points are used on patch antennas to receive a circularly polarized wave form. Both feed points receive independent linear signals which are then combined with a 90 degrees phase shift, to produce a circular signal. This applies over the full bandwidth of the antenna and greatly improves rejection of cross polarized signals (caused by multi-path reflections). Because multi-path is a significant cause of positioning error, dual feed antennas provide much higher precision than single feed antennas.
In contrast, single feed patch antennas provide a circular response only at a singular frequency (at resonance). At frequencies increasingly offset from the resonant frequency, the antenna response becomes increasingly elliptical. A single feed antenna used to receive two constellations, such as GPS (1575.42 MHz) and GLONASS (1606 MHz), is typically tuned to a mid-point frequency (1590 MHz). Single feed patch elements then have typical axial ratios at GPS and GLONASS frequencies of 7-8dB, compared with 1dB typical for a well-balanced dual feed Accutenna® antenna. Therefore a single feed antenna has poor rejection of cross polarized signals. The end result of using single feed antenna is poor precision.
