Antennas are a probaly most important component in fpv system no matter that is analog or digital FPV system. They are responsible for capturing the electrical energy from a transmitter and converting it into electromagnetic waves that can be propagated through space.
Type of antenna that is used can significantly impact the quality of the signal transmitted, and it’s is important to consider several factors when selecting an antenna for your drone.
One common urban legend is that special digital antennas are needed for digital FPV systems, which is not entirely accurate.
Both types of signals are electromagnetic waves, and antenna “doesn’t care” that they are analog or digital. 
When it comes to digital FPV systems, antennas play a critical role in that the video transmission is clear and stable. There are two main types of antennas used in our FPV systems: omnidirectional and directional antennas. Omnidirectional antennas can transmit signals in almost all directions with simillar strength making them ideal for situations where the receiver or TX in a specific location – one of them moves in difference locations. They also have limited range and they can be affected by interference/dustrubtion from other signals in the area. Directional antennas can transmit (or recieve) signals in a specific direction, making them ideal for long-range flying and minimizing interference from other signals. They are commonly used in FPV systems for this reason. The most common type of directional antenna used in FPV systems is the Extreme Cross-air antenna, which is almost flat and rectangular in shape.
Tuning of the antenna is also critical in ensuring efficient transmission and reception of signals. From well tuned set of antennas you can get more of signal reception – more range and better quality of signal (better bitrate).
Choice of antenna for digital FPV systems should be based on factors such as frequency range. You should also decide that you will need more directional antenna or omnidirectional antenna.