What is maximum unambiguous range?

Maximum unambiguous range (R_unamb = c × PRI / 2) is the maximum target distance from which a reflected pulse can return before the next pulse is transmitted. It represents a round-trip timing ceiling determined by PRF/PRI, not a guaranteed detection range (which depends on the radar range equation, target RCS, and SNR).

How is pulse energy calculated?

For a rectangular RF pulse, pulse energy equals peak power multiplied by pulse width (E_p = P_peak × PW). For example, a 1 kW peak pulse with a 1 µs duration delivers 1 mJ of energy.

Can I enter negative dBm power values?

Yes. In RF engineering, negative dBm values represent power levels below 1 mW (e.g., 0 dBm = 1 mW, -10 dBm = 0.1 mW). The calculator accepts negative dBm inputs while validating that physical linear power remains positive.

How does the calculator handle conflicting inputs?

If you provide mutually redundant inputs, the solver checks them for mathematical consistency within a 0.5% tolerance and halts with a clear notice if they conflict.

What is the relationship between duty cycle and PAPR?

For an idealized rectangular pulse, the Peak-to-Average Power Ratio is the reciprocal of the duty cycle fraction. In decibels, PAPR = -10 × log10(DC).

Pulsed RF Calculator

Solve reciprocal pulsed RF timing and power parameters, derive pulse energy, and compute maximum unambiguous radar range.

Input Parameters

Enter at least two known parameters across timing and power to solve the pulsed waveform.

Pulse Width (PW)

µs

Pulse Repetition Frequency (PRF)

kHz

Pulse Repetition Interval (PRI)

µs

Duty Cycle

Peak Power

Average Power

Results

Enter parameters on the left and click Calculate to see results.

Waveform Relationships and Governing Formulas

Duty Cycle & Timing

DC = PW / PRI = PW × PRF

PRI (µs) = 1000 / PRF (kHz). Duty cycle cannot exceed 100%.

Pulse Energy (Rectangular)

E_p = P_peak × PW

1 W × 1 µs = 1 µJ. This assumes an ideal rectangular pulse.

Max Unambiguous Range

R_unamb = c × PRI / 2

Monostatic free-space round-trip timing ceiling, not guaranteed detection range.

Average Power & PAPR

P_avg = P_peak × DC

PAPR = 1 / DC for an ideal rectangular pulse train.

dBm Conversion

P_W = 10^((dBm−30)/10)

0 dBm = 1 mW; negative dBm values are valid RF power levels.

Physical Scope

Timing, not detection

Actual radar detection range also depends on target RCS, antenna gain, losses, noise, and SNR.

Technical references: NWS Radar Basics, Tektronix Radar Fundamentals, and Rohde & Schwarz Pulsed RF Guidance.

Summary

Solve reciprocal pulsed RF timing and power parameters, derive pulse energy, and compute maximum unambiguous radar range.

How it works

Enter at least two known parameters across timing (PW, PRF, PRI, Duty Cycle) or power (Peak, Average).
Select units for power (W or dBm); negative dBm values are supported for sub-milliwatt levels.
Click "Calculate" to solve dependent parameters, pulse energy, and maximum unambiguous radar range.
Review the results, Peak-to-Average Power Ratio (PAPR), and duty cycle visual bar.
Use "Reset" to clear inputs and return to the default state.

Use cases

Size pulse-forming networks and capacitor banks by calculating energy per pulse.
Determine monostatic radar maximum unambiguous range limits from PRI or PRF.
Verify transmitter duty cycle and average dissipation against thermal limits.
Cross-derive PRF and pulse width from required duty cycle and repetition rates.
Convert between peak power and average power across linear (W) and logarithmic (dBm) scales.
Check consistency across redundant timing and power specifications before RF test execution.

Frequently Asked Questions

Last updated: 2026-09-22 · Reviewed by Nham Vu