Solve the following problem:
A radio transmitter has a power output of PT = 1 W at a frequency of 1 GHz. The transmitting and receiving antennas are parabolic dishes with diameter D = 3 m.
1. Determine the antenna gains.
2. Determine the EIRP for the transmitter.
3. The distance (free space) between the transmitting and receiving antennas is 20 km. Determine the signal power at the output of the receiving antenna in decibels.