I am building a high accuracy RTK locating system to measure my property lines and the location of buildings on the property. To achieve centimeter accuracy, it uses signals from multiple locating satellite constellations on a range of frequencies between 1164 MHz and 1610 MHz including those used for American GPS. I have several GPS antennas, including a couple from high end Trimble survey systems but am unsure if their frequency response extends far enough beyond GPS frequencies and how flat the response is.
These antennas have built-in LNA's that utilize 3VDC supplied by receivers via the coax. The antennas and the LNA's need to be tested to ensure the system meets the bandwidth requirements. Some of them can be broken down to access the antenna & LNA separately but I'm unsure how to inject the necessary LNA DC power without impacting the nanoVNA measurements.
Does anyone have recommendations for testing antennas with built-in LNA's?
Regards,
George
