Beam formers of phased array systems steer beams by introducing which type of delays in the electrical excitation spikes?

• A. Constant Delays
• B. Random Delays
• C. Inverted Delays
• D. Slope-Shaped Delays

Answer: (D)

Beam steering in phased arrays comes from creating a progressive phase difference across the elements. By making the delays between adjacent element excitations increase (or decrease) in a linear fashion, you establish a constant phase gradient across the array. This linear gradient directs the constructive interference of the radiated waves toward a specific angle, effectively steering the beam. The delays that produce this effect are proportional to the element index, yielding a slope-shaped delay pattern when plotted across the array. In practice, the required delay step relates to the element spacing and the desired steering angle, so the phase change between neighbors is linear. Therefore, slope-shaped delays are the mechanism that enables directing the beam. By contrast, identical delays offer no steering, random delays disrupt coherence, and inverted delays don’t provide the standard progressive gradient needed for a chosen direction.