Lossless GNSS/GPS signal splitter
Built-in amplifiers overcome the effects of signal loss incurred in the splitting process
The Tallysman TW16x is a range of professional-grade full GNSS band signal splitters that connects one antenna to two or four receivers.
Available with TNC or N-Type connectors.
Frequency range 1100 to 1700MHz, supporting:
- L-band correction services.
• GNSS signal distribution – connect multiple repeaters or receivers to a single antenna
• GNSS receiver testing –
• High-availability applications – all ports can provide antenna bias voltage, splitter has no single point of failure
• Network and infrastructure timing – provide accurate GNSS/GPS clock signals to multiple network timing devices
A standard GNSS/GPS signal splitter suffers insertion loss — a reduction of RF power, expressed in decibels, between a splitter’s input port and each of its output ports.
Typical insertion losses are:
- 1:2 splitter -3dB
- 1:3 splitter -5dB
- 1:4 splitter -7dB
The TW162 2-port and TW164 4-port splitters have an internal amplifier that compensates for signal losses incurred in the splitting process. Overall signal gain through the device is 0dB.
The TW163 2-port and TW165 4-port splitters have an internal amplifier that compensates for signal losses incurred in the splitting process. Overall signal gain through the device is 10dB.
Example of DC power handling using TW165 1:4 splitter.
The TW165 passes DC voltage from attached GNSS repeater/receivers through the coaxial cable to the antenna.
This voltage provides power to the low noise amplifier (LNA) in the antenna.
It accepts power from all attached receivers and selects power from one of them to power the LNA, using the following protocol:
Port #1 is given priority if its voltage is within the specified range (3.3 – 12.5 VDC).
If port #1’s receiver is disconnected, or its output voltage is outside the acceptable range, the TW165 will switch to the next port in numerical order, as long as its power and voltage are within the specified range.
If the antenna, or its feeder cable, fails and does not draw current, the TW165 will cause all ports #1-4 to draw < 1 mA, indicating an antenna fault.
- TW162 1-to-2 Port Smart Power GNSS Signal Splitter 0dB gain
- TW163 1-to-2 Port Smart Power GNSS Signal Splitter 10dB gain
- TW164 1-to-4 Port Smart Power GNSS Signal Splitter 0dB gain
- TW165 1-to-4 Port Smart Power GNSS Signal Splitter 10dB gain
A standard GNSS/GPS signal splitter can suffer the effects of two limitations
- Insertion loss — a reduction of RF power, expressed in decibels, between the splitter’s input port and each of its output ports. The insertion loss incurred with a 1:2 splitter is -3dB, with a 1:4 splitter inserting a -7dB loss.
- Only one attached GPS repeater/receiver can power the splitter and the antenna. If the repeater/receiver that is supplying the DC bias voltage fails, or is powered off, all attached receivers also fail.
While GPS signal flows from the antenna, through the splitter, to the attached receivers, a DC voltage flows in the opposite direction, from the receivers, to provide power to the low noise amplifier (LNA) in the antenna.
Usually, DC power from just one receiver is required by the antenna. One of the splitter ports is designated as “DC passthrough” with the others operating in DC-blocked mode.