You would have to buy or make a bias tee that works on that bandwidth. I
made one using stripline on a piece of G-10 pc board material. It was
designed for 1296 MHz. I don't know how well it will cover that bandwidth.
I only used it at 1296 MHz.
Zack W9SZ
On Thu, Jan 2, 2025 at 7:11?AM George via groups.io <forums=
[email protected]> wrote:
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
