It's not entirely wrong to say that an antenna is a capacitor, but it's not a good way of thinking about antennas. The problem is that once you start working wi

It's not entirely wrong to say that an antenna is a capacitor, but it's not a good way of thinking about antennas. The problem is that once you start working with radio waves, everything is a capacitor, everything is an inductor, and everything is an antenna. With a capacitor, you have two plates and you design the structure of the plates in order to create a strong electrical field between them without leaking current between the plates or leaking the electrical field into free space. Antennas are designed the opposite way---not as a "big enough capacitor", but as an incredibly bad capacitor. Instead of holding a charge, the electrical field created by the antenna leaks into free space and is lost as electromagnetic radiation, or in reverse. A good antenna is a bad capacitor. That said, the antenna does have non-trivial capacitance and inductance.