So, you have a Pi or a Le Potato setup to receive ADS-B data and track aircraft locations in real-time. Now you need an antenna. Most SDR kits come with a stock antenna that although works, is normally not tuned for optimum performance on 1090mhz.
Below are a few designs I have found helpful on my ADSB journey.
ADS-B Cantenna by ewsandor
Adsb Moxon Antenna by aseyhan
ADS-B Radome Ground Plane Antenna by markend
