GPS 15 Technical Specifications (P/N 190-00266-00)
Rev. B
Page 6
1.5.6
Antenna Specifications
Should be an active antenna with the following specifications:
Gain:
Antenna should provide between 10 dB to 40 dB net gain between the
antenna feed point and the connection to the GPS15. All amplifier gains,
filter losses, cable losses, etc. must be considered when calculating the
gain.
RF Connection:
GPS 15 RF Connection: MCX Female connector (on the GPS 15 board)
Antenna Connection: MCX Male connector (on the end of the antenna
cable)
Garmin Antenna:
GPS 27C (Garmin Part Number 010-10052-05) provides the required
MCX Male connector. Other Garmin antennas terminated in a BNC Male
connector may also be used if a Garmin MCX to BNC Adapter Cable
(Garmin Part Number 010-10121-00) is used. Place the MCX to BNC
Adapter Cable between the connector on the end of the antenna cable and
the connector on the GPS 15.
Noise Figure/Gain:
The total noise on the external antenna must be
≤
7dB with a gain between
10 dB and 40 dB. Refer to the table below.
Table 1: Gain vs. SNR for Given Noise Figure
Should be properly biased by your choice of:
Power from on-board source:
3.3 Vdc, the voltage you supply to Vin, through an on-board ~10 Ohm
current limiting resistance. The antenna must not draw more than 60mA.
Power from external source:
4.0 to 8.0 Vdc bias through the series combination of an on-board ~10
Ohm current limiting resistance and a Schottky diode. The antenna must
not draw more than 60mA.
10.0
11.0
12.0
13.0
14.0
15.0
16.0
17.0
18.0
10.0
15.0
20.0
25.0
30.0
35.0
40.0
Gain (dB)
SNR (d
B)
NF=1.3dB
NF=2.3dB
NF=3.3dB
NF=4.3dB
NF=5.3dB
NF=6.3dB
NF=7.3dB
