So you are using “f5ann active pcb antenna” which has a built-in 20 to 30 dB amplifier and a 1090 mhz SAW filter.
The graph shows 22.5 dB gain at 1090 Mhz.
You need to reduce gain considerably. To what level depends on amount of RF noise (cell phone, etc) at your location.
You have to try different gain values till you find the best, as suggested by theresjam above. Others have reported using gain values as low as 28 and as high as 45, but each system and location is unique. Trial and error is the practical solution. Alternatively run script for gain setting optimization: