One GNSS antenna can feed two receivers through a suitable RF splitter, but a matching connector is not enough to select one. The splitter must cover the required signals, provide an acceptable RF path to each receiver and use the correct DC-power arrangement. Sharing an antenna also shares its reception conditions and common upstream hardware.
This is useful when two instruments need observations from the same antenna location. It is not a way to create two independent antenna installations or a dual-antenna heading baseline. Decide whether sharing the source is actually the requirement before ordering a distribution component.
Start with the two receiver inputs
If both devices need a GNSS RF input, an RF splitter is the relevant category. If the second device only needs position messages from the first receiver, the requirement is data distribution instead. An RF splitter does not turn radio-frequency signals into NMEA messages, Ethernet data or a navigation solution.
Common path
One GNSS antenna → common RF cable → suitable splitter
Two branches
Output 1 → receiver A RF input
Output 2 → receiver B RF input
Conceptual signal path only. The required power feed and DC blocking depend on the selected equipment; this is not a wiring approval for a ResiNav terminal.
Choose the power arrangement before the connector options
An active antenna needs a suitable power source. In NovAtel’s single-antenna/multiple-receiver example, one receiver powers the antenna through the splitter while the other receiver’s DC path is blocked. Its receiver settings and input-gain limits belong to that documented equipment; they are not universal settings for other receivers.
| Intended arrangement | What to buy or specify | What can be missed |
|---|---|---|
| One designated receiver supplies antenna power. | A splitter with the required DC-pass route and blocking on the other receiver branch; confirm the antenna’s voltage/current requirements. | Powering down the designated receiver may remove antenna power from both RF branches. |
| A separate supply powers the antenna system. | The documented external-power arrangement and appropriate receiver-port DC blocking. | A DC-blocked splitter does not itself create an antenna supply; the necessary power-injection equipment must be included. |
| Either receiver is expected to power the shared antenna. | A specifically documented power-selection or redundant-feed design. | Two DC-pass connections alone do not establish safe supply sharing or automatic changeover. |
The GPS Source S12S page illustrates why the ordered configuration matters: it describes different DC routing for powered and non-powered versions. It also describes an antenna-current simulation load. Such a load can address a receiver’s detection circuit; it is not proof that the antenna is powered or that useful satellite signals reach the receiver.
For a different example, the Tallysman TW151 datasheet, Rev. 2.1 (PDF) describes blocking at both receiver ports and an external-source application. These supplier examples explain purchasing choices, not approved accessories or compatibility claims for ResiNav.
Account for the complete loss on each branch
A passive two-way split reduces the signal available at each output. Read the manufacturer’s loss definition: a value stated in addition to the division loss is not the total end-to-end loss. The TW151 specification, for example, states insertion loss as 1 dB over 3.0 dB. Do not treat that as only a 1 dB path.
Illustrative calculation, not a tested installation: assume a selected splitter has 4 dB total input-to-output loss and the cable after it adds 2 dB. That branch contributes 6 dB loss. A second branch with a 5 dB cable contributes 9 dB. These are branch losses after the splitter input, not the complete antenna-to-receiver budget or a prediction of positioning performance.
Check both branches against their respective receiver input requirements. Do not automatically buy an amplifier to cancel every loss: permitted input levels, noise performance, filtering and power arrangements still matter. Use the RF-path and cable-loss guide for the complete path calculation.
Know what the shared source cannot provide
Two receivers may provide separate processing, but the antenna, common cable, splitter and any common supply remain shared dependencies. A failure before the split can affect both outputs. A quote for two receivers and one antenna should therefore not be accepted as evidence of two independent reception paths.
Both branches also originate at the same antenna location. They do not create the spatial separation required by a dual-antenna heading installation. If the real requirement is orientation while stationary, use the heading and anti-jamming array guide to define the missing function.
Adding an anti-jamming terminal changes the input question
Do not assume a powered anti-jamming terminal behaves electrically like a receiver-powered active antenna. For example, the RN2501-AJS-4CH-DPA record publishes a 50 Ω RF output impedance. That is a useful matching parameter, but it does not establish DC tolerance at the output, permission to inject receiver bias, or approval to distribute that output to two receivers.
When comparing ResiNav configurations, keep the mitigation unit and the downstream distribution hardware as separate purchase items unless the offer explicitly includes both. Neither an element count nor a connector photograph establishes the number of supported receiver paths. Missing public information remains an open question, not a claim of non-support.
Order a defined distribution configuration
A useful line item names the splitter model and power option, required signal coverage, input-to-output loss, impedance and connectors. State which device supplies antenna power and what happens when either receiver is switched off. Include the required power-injection components and branch cables rather than assuming they arrive with the splitter.
Check published terminal dataAsk about a two-receiver terminal path