antenna connector specs

Q&A forumCategory: Questionsantenna connector specs
josegarcia asked 3 months ago

Hello. What are the voltage and current specifications on the external GNSS antenna connector? I am interested in connecting an antenna that indicates 3.4-12 VDC / 0.14A

Ardusimple Staff replied 3 months ago

Hi Jose,

simpleRTK2B is not compatible with your antenna.
simpleRTK2B provides 3.3V to the antenna with a maximum current of 100mA.

1 Answers
clive1 answered 3 months ago

140mA is a lot of current for an antenna. The DC bias on the RF input is around 3.24V unloaded, and at the connector, expect it to be less at the antenna. A typically antenna might draw 10-15mA at 3V, the design here might accommodate 50-55mA, but haven’t reviewed the circuit.
You should look at using a powered splitter or bias-tee to power this antenna.

josegarcia replied 3 months ago

This is a Trimble AG25. Do you have any links or recommendations on how to get the powered splitter or bias-tee working (no idea what those are…)

clive1 replied 3 months ago

I’ve used assorted splitters under brand names like “GPS Networking” and “W R Incorporated” which have options including an external power supply to push 5V or other values onto the antenna side feed. I’ve picked these up on eBay because the retail prices is on the high side. The ones I have will pass L1 and L2 frequencies and GLONASS. I have some HP splitters, but these tend to include L1 filters, and are powered by the highest voltage receiver attached to them.

https://www.gpsnetworking.com/
https://www.gpssource.com/products/s14-1×4-standard-gps-splitter

The bias-tee is a more simple variation, basically with a DC block on the receiver side, and the supply of a voltage via and inductor type arrangement
https://en.wikipedia.org/wiki/Bias_tee
https://www.gpssource.com/products/rf-bias-t
https://techship.com/products/bias-tee/

In the US one might also look at satellite TV splitters with explicit marking showing which connections block or pass DC, this a more “home brew” approach, but viable given the frequencies involved, as is RG6(Q) cabling with F-Type connectors and cables which can be acquired cheaply and rated/swept to 3 GHz.
https://www.solidsignal.com/pview.asp?p=SPLIT4MRV