RF, Antennas & Transmission Lines
Every rf, antennas & transmission lines calculator on CalcEngines — unit converters, derived indices and interpretive tools, each with its formula, a worked example and the reference intervals it is judged against.
10 calculators in this section
- Antenna Length CalculatorFrequency to free-space wavelength, then the lengths you actually cut: a half-wave dipole and each of its legs, a quarter-wave whip or ground-plane, a 5/8-wave vertical and a full-wave loop — in metres, centimetres, inches and feet, with the end-effect factor exposed.
- Attenuator Calculator (Pi and T Pads)Resistor values for a Pi or T attenuator pad — for equal impedances or between two different ones — derived from the image-match conditions rather than copied from a table, together with the nearest E24 or E96 parts, the attenuation and return loss those real parts actually give, and the power each resistor has to dissipate.
- Coax Impedance CalculatorCharacteristic impedance of a coaxial cable from the inner conductor diameter, the dielectric diameter and its permittivity — built from the capacitance and inductance per metre rather than quoted from a table — with the velocity factor, the delay per metre, the diameter ratio that gives 50 Ω or 75 Ω, why those two numbers and not others, and the frequency at which the cable stops carrying one mode.
- dBm to Watts CalculatorConvert between dBm, dBW and watts, milliwatts or microwatts — and the RMS, peak and peak-to-peak voltage that power makes across a 50 Ω (or any) load. Enter whichever you know.
- Free Space Path Loss CalculatorFree-space path loss in decibels from distance and frequency — or the range a given loss budget buys — with the constant derived rather than quoted, the first Fresnel zone that has to stay clear for the answer to mean anything, and the two-ray breakpoint beyond which a ground-level link stops obeying it.
- Fresnel Zone CalculatorThe first Fresnel zone radius anywhere along a radio path, the 60% of it that has to stay clear for a link to behave as if nothing were there, the earth's own bulge under the straight line with a k-factor you can set, and the knife-edge diffraction loss when the clearance is not enough.
- L-Network Impedance Matching CalculatorMatch a source resistance to a load with two reactive parts: both L-network solutions (low-pass and high-pass), their inductor and capacitor values, where the shunt part goes, the network's Q — and a sweep of how much power reaches the load either side of the design frequency.
- Link Budget CalculatorTransmit power, antenna gains, cable losses, path loss and receiver sensitivity added up into a received power and a link margin, with a verdict — plus the maximum range the budget reaches for the fade margin you ask for.
- Smith Chart Impedance CalculatorA load made of R, L and C, traced across a frequency band as a locus on the reflection-coefficient plane — with the complex impedance, Γ in magnitude and angle, VSWR, return loss and the normalised r and x at the frequency you pick, and the worst VSWR anywhere in the band.
- VSWR and Return Loss ConverterEnter any one of VSWR, return loss, reflection coefficient or mismatch loss and get the other three, with the percentage of power reflected and delivered and the two load resistances that would produce that standing wave ratio on your line.