Split GPS antenna to 2 receivers?
I need to split a powered GPS antenna between two difference receivers, but I am having some trouble finding the right component for the job. Does anyone have any recommendations? I came accross this GPS splitter but I'm not sure what most of the lingo means. Any guidance would be greatly appreciated.
Thanks.
You will theoretically loose 3dB+Insertion Loss and that will degrade the sensitivity of the GPS.If you are ready to take this risk, no problem.
If you place an LNA after the antenna and before the 3dB splitter (for the LNA let's assume 0.5dB NF and 15dB gain), the total increase of the combined noise figure will be 0.62dB (only 0.12dB increase for LNA + Splitter). Myself I am using a single GPS antenna followed by an LNA and a 4 way splitter, going to 4 receivers.
The original post says "powered" GPS antenna, which apparently means an active antenna. If it has sufficient gain, an additional LNA may be expendable. The GPS receiver bias options should be configured so that either one is supplying the antenna and the other doesn't short the supply. Or both sending the supply voltage if possible reverse feed is permitted.
Because you use an active antenna, 3-4 dB of loss will not hurt the performance much(the loss of your selection is specified as 0.2+3=3.2 dB). You can put one more LNA after the antenna if required.
The actual issue is to select one of the receivers to supply the antenna and prevent the other not to cause short circuit between different voltage levels(most receivers have a voltage source to supply the connected antenna, the voltage levels may vary from one to other). If your current setup is OK, the component you selected will allow you to add second receiver with no additional components. You notice the labels on the module, connect your current receiver through the way labeled "DC pass", connect the new receiver through DC blocked way.
Blocked way has a load emulating the antenna, because some receivers give antenna error if they do not see any loading. If you do not need such emulation, there are other splitters blocking DC without load emulation. You can select one supporting the GPS frequency band.