Question 1
Antenna & Wave PropagationArray Phase
A two-element array has elements separated by lambda/2. To make their contributions add in phase in the direction along the array axis, the required progressive excitation phase can be chosen as approximately?
Correct Answer: C. 180 degrees
Explanation: A lambda/2 path difference produces 180 degrees propagation phase difference; an opposite 180 degrees excitation progression can compensate it for end-fire addition.
Reference: Standard antenna and wave propagation: array phase