Pulse Width Calculator
Calculate the radar pulse width required to achieve a specified range resolution for a pulsed radar system.
1
Inputs
Live
Math
3
Related
Enter parameters and click Calculate to view results
Formula & Theory
τ = 2ΔR/c, B ≈ 1/τThis formula is used to calculate antenna parameters for pulse width calculator.
Overview
The Pulse Width Calculator determines the unmodulated transmit pulse duration ($\tau$) and signal bandwidth ($B$) required to achieve a target range resolution ($\Delta R$) in pulsed radar systems. It provides essential baseline parameter calculations for radar waveform design and receiver bandwidth sizing.
Input Guide
Enter Desired Range Resolution exactly in the units shown by this pulse width. Check the operating band, unit prefix, and decimal position before calculating; these are the inputs used by the formula.
- Desired Range Resolution — use m.
Output Guide
The results describe the calculated pulse width values for the inputs you entered. Check each value against the available space, selected components, feed system, and operating conditions before making a final design decision.
How This Calculator Works
The Pulse Width uses τ = 2ΔR/c, B ≈ 1/τ. Supply Desired Range Resolution (m) in the displayed units, then use the calculated values as the first engineering target for this radar engineering design or analysis.
Design Notes
In simple unmodulated pulsed radar, range resolution is directly constrained by the pulse width ($\Delta R = \frac{c \cdot \tau}{2}$). Shorter pulse widths improve range resolution and reduce minimum blind range ($R_{min} = \frac{c \cdot \tau}{2}$), but reduce total transmitted energy per pulse ($E = P_{peak} \cdot \tau$), decreasing detection range unless peak transmitter power ($P_{peak}$) is substantially increased. Sizing receiver bandwidth to approximately $B \approx \frac{1}{\tau}$ balances noise admission with pulse shape fidelity.
Build and Tuning Notes
If fine range resolution requires an impractically short pulse width that compromises total average power or exceeds peak power limits, consider pulse compression (chirp or phase coding). Pulse compression decouples range resolution from pulse duration, allowing high pulse energy via long duration alongside fine range resolution via wide signal bandwidth. When measuring physical hardware, account for transmitter rise/fall times and matched-filter bandwidth limitations.
Frequently Asked Questions
What is the relationship between pulse width and radar range resolution?
Range resolution is proportional to pulse width ($\Delta R = \frac{c \cdot \tau}{2}$). A shorter pulse width enables the radar to distinguish closely spaced targets along the same line of sight.
How does pulse width affect minimum blind range?
During pulse transmission, monostatic radar receivers are typically blanked or duplexed to protect sensitive front-end low-noise amplifiers (LNAs). The minimum detectable range is thus governed by pulse duration ($R_{min} = \frac{c \cdot \tau}{2}$).
Why does a shorter pulse width require wider RF bandwidth?
By Fourier analysis, short temporal pulses possess a broad frequency spectrum ($B \approx \frac{1}{\tau}$). Achieving finer range resolution demands higher RF and IF receiver bandwidth to process the rapid pulse envelope without distortion.
What is the trade-off between pulse width and detection range?
Shorter pulses contain less total energy per pulse ($E = P_{peak} \times \tau$). Assuming constant peak power, shortening the pulse reduces the overall SNR at the receiver, which decreases the maximum detection range.
How does pulse compression overcome the pulse width trade-off?
Pulse compression techniques (like linear frequency modulation or phase coding) transmit long pulses to maintain high average power while applying wideband modulation. Upon reception, matched filtering compresses the pulse to achieve fine range resolution without high peak power demands.
Alex Warren
B.Sc. in Electrical & Electronic Engineering (EEE)
Alex specialises in antenna design and wave propagation. His expertise helps ensure these calculators present practical RF concepts, useful design estimates, and clear engineering guidance for students, HAM operators, and wireless professionals.