In phased arrays, what is the purpose of nulling?

• A. To increase gain uniformly in all directions
• B. To broaden the beamwidth unnecessarily
• C. To create a directional null to suppress interference
• D. To shift operating frequency

Answer: (C)

The idea here is shaping the signal pattern to reduce energy from unwanted directions. In a phased array, you control how the signals from all elements combine by adjusting their phases and amplitudes. Nulling uses those adjustments to place a deep null, or very low gain, in the direction of an interfering signal. By doing so, the array suppresses the interference while keeping the main beam aimed at the intended direction, improving the signal quality or reception.

So this choice describes creating a directional null to suppress interference, which is exactly what nulling accomplishes. It’s not about boosting gain everywhere, broadening the beam unnecessarily, or changing the operating frequency.