What does Pulse Width determine in radar systems?

• A. Maximum range and peak power
• B. Pulse repetition rate
• C. Minimum range and average power out
• D. Resolution and clutter level

Answer: (C)

Pulse width is the duration of each transmitted radar pulse. That duration fixes how long the receiver must wait before it can listen for echoes, which sets the minimum range you can detect. If the pulse lasts longer, echoes from closer targets would arrive while the radar is still transmitting, so they can’t be distinguished—roughly, the minimum range is Rmin ≈ c × t_p / 2. Pulse width also controls how much energy is sent per pulse: energy per pulse equals peak power times the pulse width. The average power radiated is that energy per pulse multiplied by the pulse repetition frequency, so increasing the pulse width (with peak power and PRF held constant) raises the average power out. So, the two main effects of pulse width are establishing the minimum range and controlling the average power output. It doesn’t directly set maximum range or the PRF, and while shorter pulses improve range resolution, the essential link here is to minimum range and average power.