Post-lab Questions 1. What is a difference between gain of an antenna and direct
ID: 2249859 • Letter: P
Question
Post-lab Questions 1. What is a difference between gain of an antenna and directivity of an antenna? 2. If pyramidal horn antenna (having largest dimension as 10 cm) is mounted on rectangular ground plane (whose dimensions are of 50cm*50cm), what would be 'D' in far field region equation? 3. Draw equivalent lump element circuit for an antenna. 4. To increase directivity/gain of your antenna system, what would you do? Increase the size of an antenna or reduce the size of an antenna? 5. Define E-plane and H-plane. 6. What will happen to following parameters, if we increase the frequency from 10 GHz to 12 GHz, Directivity GainExplanation / Answer
1) Directivity, in simple terms, is (max)gain obtainable in a particular direction. As you might have guessed, isotropic antennas have a directivity of 1 which is useless.
All practical antennas are directive, meaning they are designed to radiate in one particular direction. It means that they concentrate the gain of that antenna in that one direction.
The physical values of both gain and directivity are almost same. Mathematically, they are related by only one factor, the efficiency. Efficiency lies between 0 and 1.
Gain of an antenna (in a given direction) is defined as “the ratio of the intensity, in a given direction, to the radiation intensity that would be obtained if the power accepted by the antenna were radiated isotropically.
Directivity and gain differ only by the efficiency