The current pattern of a very small dipole antenna (usually where length L satisfies λ/50 < L < λ/10) can be approximated by which type of distribution?

For measuring the antenna far-field pattern, what must be the minimum distance R between the transmitting and receiving antennas, where D is the maximum dimension of the antenna and λ is the wavelength?

In a typical 14-element mobile satellite array antenna configuration, if three elements are activated to form a dynamic beam, how many elements remain deactivated?