The effective area or effective aperture of a receiving antenna expresses the portion of the power of a passing electromagnetic wave which it delivers to its terminals, expressed in terms of an equivalent area. For instance, if a radio wave passing a given location has a flux of 1 pW / m2 (10−12 watts per square meter) and an antenna has an effective area of 12 m2, then the antenna would deliver 12 pW of RF power to the receiver (30 microvolts rms at 75 ohms). Since the receiving antenna is not equally sensitive to signals received from all directions, the effective area is a function of the direction to the source. COUNT 4
QSN1 What is the portion of something that is reached by the radio transmission called? ANS1 aperture QSN2 What effects the function of signals received by an antenna? ANS2 direction QSN3 What is a measure of the power of an antenna? ANS3 microvolts QSN4 How much power will be delivered to the reciever if the antenna has an effective area of 12 m/2? ANS4 12 pW of RF power