rftools.io

RF & Microwave Calculators

17 free online calculators for engineers and makers.

Microstrip Impedance

Calculate microstrip transmission line impedance using Hammerstad-Jensen equations. Get Z₀, effective dielectric constant, and propagation delay for PCB trace design.

Link Budget

Calculate RF link budget: transmit power, free space path loss, antenna gains, and received signal level. Determine link margin and maximum range.

VSWR / Return Loss

Convert between VSWR, return loss, reflection coefficient, mismatch loss, and reflected/transmitted power percentage for RF impedance matching.

dBm Converter

Convert dBm to watts, milliwatts, dBW, dBμV, and volts RMS. Essential RF power unit conversion tool for signal levels and link budgets.

Cascaded NF

Calculate cascaded noise figure for a chain of RF stages using the Friis formula. Essential for LNA and receiver chain design.

Skin Depth

Calculate the skin depth (penetration depth) of electromagnetic fields in conductors as a function of frequency and material properties.

Wavelength / Frequency

Convert between frequency, wavelength, and wave number in free space or medium. Calculate half-wave and quarter-wave lengths for antenna and transmission line design.

Coax Impedance

Calculate coaxial cable characteristic impedance, capacitance, inductance per unit length, and cutoff frequency from inner/outer conductor dimensions and dielectric.

Attenuator Designer

Design Pi (π) and T attenuator pads for any attenuation value and impedance. Returns standard resistor values for both topologies with nearest E24 values.

Smith Chart

Interactive Smith Chart for impedance matching and RF network analysis. Enter load impedance to visualize reflection coefficient, VSWR circle, and normalized impedance.

Q Factor

Calculate quality factor (Q) for inductors and capacitors, resonant circuit bandwidth, and equivalent series resistance

Waveguide

Calculate cutoff frequencies for rectangular waveguide TE and TM modes, guide wavelength, and phase velocity

Free-Space Path Loss

Calculate free-space path loss (FSPL) using the Friis transmission equation for wireless link budget analysis

Radar Range

Calculate maximum radar detection range using the radar range equation, including RCS, antenna gain, noise figure, and bandwidth parameters

PA Efficiency

Calculate RF power amplifier efficiency including power-added efficiency (PAE), drain efficiency, DC power consumption, and heat dissipation

IMD / IP3

Calculate third-order intercept point (IP3), intermodulation distortion products, and spurious-free dynamic range for RF amplifiers and mixers

Phase Noise to Jitter

Convert oscillator phase noise (dBc/Hz) to RMS jitter and cycle-to-cycle jitter by integrating over a specified offset frequency range