8.2 External Antenna
8.2.1 Recommended Parameters
General GPS active antenna specification:
Limitations:
•
Supply voltage according to voltage fed into VANT pin (5 V max.)
•
Supply current 50 mA (max.)
Recommendations:
•
Gain
≥
20 dB (should not exceed 35 dB)
•
Noise
figure
≤
1.5 dB
The recommendations apply to the majority of active antennas that can be found in the
market. The quality and suitability of the GPS antenna chosen is of paramount impor-
tance to the overall sensitivity of the GPS system.
The system design needs to reflect the supply voltage of the antenna. If the supply
voltage is equal to Vcc, Vcc can be connected to VANT. If the antenna requires a
different supply voltage, the antenna bias can be provided through the VANT pin.
V1.5 – Dec-09
User’s Manual
Page 25 of 37
