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Basic
Description
The GPS35
GPS Antenna Amplifier was designed to extend the
distance a GPS antenna can be located from a GPS
receiver.
GPS
receivers operate with very small signal levels, often
below -150 dBm. Also, they tend to have a limited
dynamic range, meaning the signal level must be within
set limits. A signal must not be too high or too
low in level.
Typically,
the antenna can only be placed 5 - 50 meters or so
from the GPS receiver, otherwise the GPS signal will be
attenuated by the loss in the coaxial cable.
The GPS35
has 32 dB to 35 dB of gain allowing this cable length to be
extended. Lengths of up to 350 meters are possible
without any degradation to the GPS signal.
The GPS35 is
simply inserted in series with the coaxial cable, as
close to the antenna as possible. The GPS35 will
be powered by the voltage sent up the inner wire of the
coaxial cable by the
GPS receiver. The GPS35 operates from 3 to 12
volts and only consumes 19 mA, well within the
capabilities of most GPS receivers. The GPS35 will then
send this same voltage to the active antenna to power
the antenna's low noise amplifier.
The GPS35 is
fully configurable to suit individual systems. If
the GPS receiver doesn't send out a voltage, the GPS35
can be powered from an external DC power supply.
In this mode, no DC flows down to the GPS receiver.
Also the
GPS35 can work with passive antennas that mustn't have
any voltage applied to them. In this case a jumper
is simply removed by the customer.
The GPS35
can also work with different voltage systems. A
GPS receiver that sends out 5V or 12V can be interfaced
to an antenna that may only need 3V.
Band Pass
Filter Included
The GPS35
operates on all the GPS frequencies of the USA
system, Glosnass (Russia) and the European Galileo
system.
The GPS35
includes a bandpass filter that only allows the GPS
frequencies through, but blocks cellular or other signals.
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The picture on the left shows the frequency
response of the GPS35. The gain is 34 dB
and there is over 35 dB of rejection at the
mobile phone frequencies.
This allows the GPS35 to be used close to
cellular towers without the cellular signals
getting into the GPS receiver.
Also the amplifiers inside the GPS35 are low
noise meaning the GPS signal is unaffected by
the insertion of the GPS amplifier. |
Specifications
|
Specification Parameter |
Specification |
Comments |
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Usable Frequency Range |
1200 to 1607 MHz |
|
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Input and Output Impedance |
50 Ω nominal |
|
|
Gain |
35 dB ± 3 dB |
|
|
Input and Output return loss |
> 10 dB typical |
|
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Stopband Rejection |
35 dB min from 0 to 900 MHz and > 1900 MHz
|
Typically > 45 dB rejection |
|
Noise Figure / Reverse Isolation |
< 3 dB / > 65 dB |
|
|
1 dB Compression |
-15 dBm |
|
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DC Voltage Required |
3.0 V to 5.5 V (Other voltages on special
request) |
|
|
DC Current of amplifier |
19 mA Max |
Typically < 17 mA |
|
Max DC Current to antenna |
75 mA |
With 5V going to antenna |
|
Max DC Current to antenna |
30 mA |
With 3V going to antenna |
|
Connectors |
N type female as standard. |
Other connectors on special order |
|
Size |
158.0 mm x 30.0 mm x 26.2 mm |
Including the connectors |
|
Weight |
250 grams |
|
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Environmental |
-20 °C to +60 °C |
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Option 01 |
Gain reduced to 20 dB and current to 12 mA |
Special Order
Only |
|
Option 02 |
DC passes to Antenna (input port) |
Now fitted as standard |
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Option 03 |
External 3 - 5 volt power supply connection |
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Option 04 |
Power supply for option 03. 100 – 240 VAC |
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