Topic: Antennas and Wave Propagation
A parabolic reflector antenna used for reception of data is 1 meter in diameter and operates at 30 GHz. The far field distance of this antenna for a quadratic phase error of 22.5 degree is:
- A. 200 meter
- B. 50 meter
- C. 100 meter
- D. 150 meter
Answer: A. 200 meter
Explanation: Diameter = 1 m, f = 30 GHz, phase error = 22.5 degree. Far field = 2 * D² / lambda = 2*(1)^2 / 0.01 = 200 m (lambda = c/f = 0.01 m).