Integrating a CRPA terminal into a UAV payload
Ground plane, mounting height, cable loss and power budget decide whether a 130 g terminal performs like its datasheet or like a bare patch antenna.
The ground plane is part of the antenna
An array terminal is specified on a defined ground plane. Mount it on a small carbon plate, or directly onto a composite fuselage with nothing conductive beneath, and the pattern is no longer the pattern in the datasheet — low-elevation gain drops and the null depths you paid for shrink.
Give the terminal a continuous conductive plane at least as large as its own footprint, and keep it flat. This is the single most common reason a terminal underperforms its specification in the field.
Where you mount it matters more than usual
The array needs a clear view of the sky, and it needs the same view from every element. Anything that shadows part of the aperture — a mast, a camera gimbal at certain angles, a folded arm — distorts the geometry the nulling depends on.
Keep it away from your own transmitters as well. A video link or telemetry radio a few centimetres from a GNSS front end is itself an interference source, and it is the one interference source you can eliminate by moving it.
Cable and connector budget
Terminals in this range output −70 to −60 dBm into 50 Ω, which is a comfortable level for an integrated receiver, but not one you can spend carelessly. Keep the run short, use a cable rated for the band, and account for every connector transition.
If your receiver needs a different level, say so before ordering — matching this at design time is trivial, and awkward once the airframe is built.
Power is a real constraint, not a footnote
Six watts at four elements is easy on almost any platform. Forty watts at sixteen elements is a genuine load that affects endurance and thermal design. Check the figure against your continuous power budget, not your peak, and confirm the terminal has somewhere to shed heat if it is enclosed.
Test before you trust it
Verify the installation with the terminal on the actual airframe, not on a bench. Confirm the receiver reaches its normal C/N₀ across the visible constellation with the aircraft powered up and all onboard radios transmitting. If C/N₀ is already several dB low before anyone jams anything, the installation is eating your margin, and the array will run out of it sooner than the datasheet suggests.