GPS Antenna Amplifiers

A GPS Amplifier is connected as close to the GPS aerial as possible.  It allows longer cable lengths to be used between the antenna and the GPS receiver.  However, an amplifier should be used with caution.  The following list, lists important features that should looked for when purchasing a GPS antenna amplifier.

• Low noise.  Unless the amplifier is low noise, the amplifier will simply add more noise to the signal and no benefit will be had.  All our amplifiers are ultra low noise types.
• Good matching at 50 ohm impedance.   GPS receivers all have 50 ohm impedance.  Amplifiers should present a good 50 ohm match both to the antenna and the receivers.  All our amplifiers are matched for 50 ohm operation.
• High Gain.  A high gain GPS amplifier allows cables lengths up to 350 meters to be used.  Our GPS amplifiers has gains up to 45 dB.  The actual gain can be specified by the user.
• Frequency band limited to GPS frequencies only.  A wideband amplifier will simply amplifier noise and other signals as well as the signal of interest.  This could overload the GPS receiver and stop it from working.  Our GPS amplifiers incorporate band-pass filters that only allow the wanted GPS frequencies to be amplified. 
• L1 and L2 coverage.  Our amplifiers cover both the L1 and L2 frequencies allowing them to be used for both commercial and military applications.
• Good reverse isolation.  Reverse isolation of an amplifier means no unwanted signals, that may be on the GPS receiver, are not transmitted to the GPS antenna.   Our amplifiers all have good reverse isolation.
• DC feedthrough.  Our GPS amplifiers has DC feed-through which allows the DC present on the GPS receiver to be fed to the active antenna.
• Versatility.  DC feed-through is important when using an active antenna, but is not wanted in some situations, e.g. when there is a passive receiver  or when the antenna is a special voltage type.  On our GPS35, it is possible to allow or disallow DC feed-through simply by selecting jumpers on the amplifier.
• Multi-voltage operation.  GPS receivers operate from 3 to 12V.  It's important that a GPS amplifier can operate at different voltages.  The GPS35 operates from 3.0 volts to 12 volts.
• Rugged Construction.   Often GPS amplifiers are used on airplanes, ships and other moving vehicles.  Our amplifiers are all made from a solid piece of aluminum which is milled out for the electronic components and connectors.
• Mutl-Connector types.  Our amplifiers are available in SMA, TNC, BNC and N type connectors.

GPS Antenna Splitters

A GPS splitter allows one aerial to be used for multiple GPS receivers.  Again, however, it is important that a splitter have the correct features.

The following, lists important features that should looked for when purchasing a GPS antenna splitter.

• Many Outputs.  Our GPS30 has four outputs allowing up to four GPS receivers to be used with one antenna.  If less than four receivers are used, the un-used ports can simply be left un-terminated.
• Low noise.  Unless the splitter is low noise, the splitter could add more noise to the signal and no benefit will be had.  All our splitters are ultra low noise types.
• Good matching at 50 ohm impedance.   GPS receivers all have 50 ohm impedance.  Splitters should present a good 50 ohm match both to the antenna and the receivers.  All our splitters are matched for 50 ohm operation.
• Gain.  A GPS splitter shouldn't have any loss.  Our splitters have gains of 0 dB or optionally 10 dB. 
• Frequency band limited to GPS frequencies only.  A wideband splitter could allow noise and other signals to overload the GPS receiver.  Our GPS splitters incorporate band-pass filters that only allow the wanted GPS frequencies to be passed through. 
• L1 and L2 coverage.  Our splitters cover both the L1 and L2 frequencies allowing them to be used for both commercial and military applications.
• Good reverse and channel isolation.  Reverse isolation of a splitter means no unwanted signals, that may be on the GPS receiver, are not transmitted to the GPS antenna.    Also, there should be good isolation between each channel so the separate GPS receivers are all isolated from each other. Our splitters have good reverse and channel isolation.
• DC feedthrough.  Our GPS splitters has DC feed-through which allows the DC present on the GPS receiver to be fed to the active antenna.
• Versatility.  DC feed-through is important when using an active antenna, but is not wanted in some situations, e.g. when there is a passive receiver  or when the antenna is a special voltage type.  On our GPS30, it is possible to allow or disallow DC feed-through simply by selecting jumpers on the splitter.
• Multi-voltage operation.  GPS receivers operate from 3 to 12V.  It's important that a GPS splitter can operate at different voltages.  The GPS30 operates from 3.0 volts to 12 volts.  It can even work with different GPS receivers having different voltage outputs.
• Automatic Operation.  The GPS30 will take its supply voltage from any of the four ports.  Therefore GPS receivers can be connected to any port, allowing more versatility.
• Internal Load resistors.  Many GPS receivers will report an error if the antenna current is low.  To prevent this, our GPS30 incorporates load resistors that can be placed in circuit by selecting jumpers.  The load resistor simulates an active antenna to the GPS receiver, preventing any errors.
• Rugged Construction.   Often GPS splitters  are used on airplanes, ships and other moving vehicles.  Our splitters are all made from a solid piece of aluminum which is milled out for the electronic components and connectors.
• Mutl-Connector types.  Our splitters are available in SMA, TNC, BNC and N type connectors.