A growing suite of free, browser-based RF and antenna engineering calculators. No sign-up required — results are instant and run entirely in your browser.
Hammerstad–Jensen synthesis for microstrip trace width, effective permittivity (εeff), phase velocity, and guided wavelength. Supports custom substrates.
Open calculator →Closed-form inset-fed microstrip patch antenna calculator. Computes patch width W, patch length L, inset feed depth y₀, notch gap g, and effective permittivity for any substrate and frequency.
Open calculator →Conformal mapping calculator for CPW characteristic impedance Z₀, effective permittivity εeff, phase velocity, and guided wavelength. Interactive slider controls update the live cross-section diagram in real time.
Open calculator →Skin depth, surface resistance and surface impedance of 17 conductors from 1 Hz to 1 THz. Covers plated finishes such as ENIG and silver plate, exact round-wire AC resistance, and PCB trace loss with surface roughness.
Open calculator →Convert between wavelength (λ), frequency (f), and phase velocity. Supports free-space and dielectric-filled media.
Open calculator →Calculate half-wave and quarter-wave dipole element lengths from operating frequency with velocity factor correction.
Open calculator →Method of Moments simulator for half-wave, off-center-fed and inverted-V dipoles. Finds the resonant length for your wire, then shows impedance, SWR, current, gain, takeoff angle and 3D patterns over free space, perfect or real ground.
Open calculator →Quarter-wave monopoles and ground-plane antennas with 3–8 radials. Solves the radial droop angle for a direct 50 Ω feed and shows impedance, SWR, gain, efficiency and takeoff angle, with optimizer and tolerance yield.
Open calculator →DL6WU or uniform Yagis from 2 to 30 elements, tuned by a method-of-moments wire solver. Gives the cut list with boom correction, gain, front-to-back, SWR and radiation patterns, with hairpin and quarter-wave matching and an optimizer.
Open calculator →Log-periodic dipole array design from a frequency range and a gain target. Gives element lengths and spacings, feeder impedance and boom spacing, a cut list and NEC deck, and solves gain, SWR, front-to-back and patterns across the band.
Open calculator →Calculate the first Fresnel zone radius at any point along a link path. Determine minimum clearance for line-of-sight operation.
Open calculator →Interactive Smith chart for impedance matching network design. Add series and shunt inductors, capacitors, and resistors — the impedance trace, S11, VSWR, |Γ|, and circuit schematic all update in real time. Drag to reorder components.
Open visualiser →Complete patch antenna design reference — step-by-step equations for patch width W, effective permittivity εeff, length extension ΔL, resonant frequency, inset feed depth y₀, input impedance, gain, bandwidth, and substrate selection guide.
Open reference →Butterworth, Chebyshev and Bessel LC low-pass filters. Finds the order from your stopband attenuation, gives every L and C value with E12/E24/E96 parts, and plots S21, return loss, group delay and step response.
Open calculator →LC high-pass filters by exact transformation of the Butterworth, Chebyshev and Bessel prototypes. Series-C or shunt-L topology, standard part values, SPICE netlist and Touchstone export.
Open calculator →Series and parallel resonator LC band-pass filters from a centre frequency and bandwidth or from band edges. Sizes the order for both stopbands, warns on narrow bands and shows the RF-burst envelope response.
Open calculator →Reject an interferer with an LC band-stop ladder or a single notch trap. Gives the trap L and C values, the real notch depth for your inductor Q, standard parts and the interferer transient.
Open calculator →Calculate dB signal loss as a function of distance and frequency in free space. Essential for any wireless link budget.
Open calculator →End-to-end link budget calculator. Enter EIRP, path loss, antenna gains, and cable losses to find received power and SNR margin.
Open calculator →Two-way conversion between dBm, dBW, W, mW and µW, plus Vrms, Vpp, dBµV and current at 50 Ω, 75 Ω or any impedance. Includes a power scale with everyday reference levels and a printable dBm to watts table.
Open converter →Power density, E and H field, and the safe compliance distance against FCC, ICNIRP 2020/1998 and Safety Code 6 limits. Includes a site exclusion-zone map, multi-transmitter totals, amateur radio mode presets and a downloadable PDF report.
Open calculator →Bi-directional conversion between VSWR, return loss (dB), reflection coefficient (Γ), and mismatch loss. Includes power loss percentage.
Open calculator →Cascaded noise figure using the Friis formula. Convert between noise figure (dB) and noise temperature (K). Calculate system sensitivity.
Open calculator →We add new tools monthly. Request one or explore our RF education library.