Dish Antennas

To achieve maximum gain from an antenna, you need to use a dish. The gain of a dish
is equal to (πD/λ)2 × N, where D is the diameter of the dish, λ is the wavelength, and N
is efficiency. Dish antennas are used extensively in cellular networks to move traffic to
and from, and between cell sites. More commonly we see dish antennas installed for
the reception of satellite TV.
Gain is limited by the tolerance of the reflective surface. Gains of between 30 and 50
dBi are achievable with 1° beamwidths. As frequency increases, particularly above 10
GHz, weather effects become very significant. We study this in Chapter 15, which deals
with fixed access wireless.