GPSAntenna™ Model 501
Introduction
The NovAtel GPSAntenna Model 501 is designed to provide superior
performance over a wide range of GPS applications. It incorporates
the following features:
• L1 Center Frequency at 1575.42 MHz
• Enhanced Multipath Rejection
• Internal Low Noise Amplifier (LNA)
• Internal Interference Rejection Filter
• Low Noise Figure
• Small Size (11.4 cm Diameter x 5.7 cm Height)
• Single External TNC Connector
• Environmentally Sealed Radome
• Tripod 5/8" Coarse Thread Center Mounting
• Four Screw Fixed Mounting (Groundplane or Platform)
General
The GPSAntenna receives the C/A code signals from the NAVSTAR
satellites. These signals are Right Hand Circular Polarization (RHCP)
signals centered at 1575.42 MHz. The antenna module rejects the
unwanted Left Hand Circular Polarization (LHCP) and out-of-band
signals. The antenna then filters, amplifies and transfers the signals to
the GPSCard™ for further processing. Figure 1 shows the typical
antenna Elevation Gain Pattern for RHCP and LHCP signals.
Typical GPSAntenna Elevation Gain Pattern
Right Hand Circular Polarization
10
0
-10
-20
10
0
-10
dBic
dBic
10
0
-10
-20
10
0
-10
dBic
dBic
Typical GPSAntenna Elevation Gain Pattern
Left Hand Circular Polarization
Figure 1 GPSAntenna Elevation Gain Pattern
Note: These cables are selected to meet GPS performance
requirements. If alternate coaxial cable type and lengths are required,
use care in selecting appropriate cable replacement. NovAtel only
guarantees operation with NovAtel-supplied cables.
GPSAntenna Specifications
Electrical
Center Frequency 1575.42 MHz
Bandwidth 10 MHz (-1 dB)
Gain Pattern > 0 dBic to 75˚ from vertical
> -3 dBic to 85˚ from vertical
< -10 dBic 120˚ from vertical
Polarization Right hand circular at all angles above the
horizon
Axial Ratio < 1 dB
LHC Multipath Rejection > 10 dB
Phase Center Stability < 10˚ RMS (5 mm) above 15˚ elevation
Physical
Size 114 mm diameter x 58.6 mm height
Weight 300 grams
Mounting Tripod 5/8 inch Coarse Thread
Four screws #6-32
Environmental
Operating Temperature -40˚C to +85˚C (-40˚F to +185˚F)
Storage Temperature -50˚C to +95˚C (-58˚F to +203˚F)
Operating Humidity 100%
Altitude 5,000 meters
Low Noise Amplifier
Power 99 mW
(4.5 ±0.5Vdc @ 22 mA max)
Gain 23 dB
Noise Figure 3.0 dB typical (3.6 dB maximum)
Interference Rejection >15 dB for f > 1715 MHz
f < 1435 MHz
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