Novatel OM-20000077 user manual Geodetic Active Antenna, Antenna Specifications Appendix C

Antenna Specifications					Appendix C
	Table 12: Antenna Gain Depending on Cable Length Required
	Cable PNs	ANTENNA GAIN	CABLE TYPE	MAX. LENGTH a	MIN. LENGTH
	217-601730-XXX	0 dB (no LNA)	RG-58 Low Loss	3 meter (3 dB)	0 feet
	217-601730-XXX	+12 dB	RG-58 Low Loss	20 meter (12 dB)	0 feet
	217-601730-XXX	+36 dB	RG-58 Low Loss	65 meter (36 dB)	50 meter (28 dB)

a.A 1 dB loss for the coaxial cable is usually required between the RG-58 cable and the GPS Receiver MCX connector and it is included in attenuation number in parentheses. If the distance between the antenna and the GPS receiver needs to be longer than 65 m, you should select another type of coaxial cable with a lower loss per meter.

The +26 dB and +36 dB antenna can accept a supply voltage between 5 and 18 VDC. It is recommended to compute the drop in the coaxial cable so the active antenna will always see the minimum operating voltage of 4.5 Volt. Table 13 lists the current taken by each of these antenna.

Table 13: Typical Current Consumption Versus Antenna Gain

Antenna Gain	Current Consumption
+12 dB	20 mA
+26 dB	35 mA
+36 dB	50 mA

C.2 Geodetic Active Antenna

For DGPS applications where <1 m accuracy is required, it is strongly recommended you use an active geodetic GPS antenna if possible. In the event where the cable length between the receiver and the antenna is very short (less than one meter), a passive antenna could then be considered. Table 14 lists the specifications for recommended passive antennas. Complete drawings are at the end of this appendix.

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