Fundamental everyday RF utilities. Free to use. Type any input — cards auto-update.
Pi-pad Attenuator (symmetric)
Matched pad for a single reference impedance Z0. Enter target attenuation to synthesise, or enter resistors to analyse.
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T-pad Attenuator (symmetric)
Matched pad for a single reference impedance Z0. Enter target attenuation to synthesise, or enter resistors to analyse.
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L-pad Match (2 resistors)
Impedance match between two real impedances using one series and one shunt resistor. Auto-selects topology (shunt at IN if Z2>Z1, else shunt at OUT).
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Potential Divider (Vout, I, R1, R2)
Ideal 2‑resistor divider. Edit Vin/R1/R2 to analyse Vout and current, or edit Vout to auto-adjust the divider ratio.
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RF Power Converter
Convert RF power between logarithmic power, linear power, voltage and current for a real reference impedance.
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VSWR / Return Loss / Γ
Enter any one quantity; the others update automatically. Mismatch loss is the power lost solely from reflection.
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Complex Z ↔ S11 / Γ
Convert a complex impedance to reflection coefficient/S11, or enter Γ magnitude and angle to recover impedance.
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Reactive L-Match Designer
Match two real impedances at one frequency. The shunt element is placed on the higher-resistance side; both low-pass and high-pass component choices are shown.
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Reactive Pi-Match Designer
Low-pass Pi network using a selectable input-side Q. Useful for narrow-band RF impedance transformation and PA output matching estimates.
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Reactive T-Match Designer
Low-pass T network using a selectable input-side Q. The virtual resistance is above both terminations.
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RLC Impedance / Reactance
Calculate reactances and both series and parallel RLC impedance at the operating frequency.
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LC Resonance / Q / Bandwidth
Edit L and C to calculate resonance. If you edit resonant frequency, C is solved while L is held constant. Q uses the entered series resistance.
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Cascaded Gain / Loss / RF Power
Quick four-stage RF power budget. Use positive values for gain and negative values for cable/filter/attenuator loss.
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Cascaded Noise Figure — Friis
Four-stage receiver noise calculation. Enter gain and noise figure for each stage; losses may be entered as negative gain with the appropriate passive NF.
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Cascaded IP3 / P1dB Budget
Three-stage linearity budget using stage gain, OIP3 and output P1dB. The P1dB result is a first-order input-referred estimate.
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Ground-backed CPW Impedance
Quasi-TEM characteristic impedance and effective permittivity for a grounded coplanar waveguide (signal trace with side grounds, backed by a ground plane).
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Microstrip Impedance
Wadell/Wheeler closed-form approximation including copper thickness correction. Edit Z0 to solve for width w.
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Microstrip Optimal Mitre
Douville & James empirical optimum for a 90° microstrip bend. Returns mitre diagonal M (mm).
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Stripline Impedance (asymmetric)
Asymmetric stripline approximation (Wadell form): edit Z0 to solve for width w. Stripline εeff ≈ εr.
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Coaxial Cable Characteristic Impedance
Ideal homogeneous coax calculation from conductor diameters and dielectric constant.
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Transmission-Line Electrical Length
Convert physical line length into electrical phase, propagation delay and guided wavelength.
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Transmission-Line Input Impedance
Lossless line transform for a complex load. Useful for checking cable, fixture and PCB-line impedance transformations.
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Quarter-Wave Transformer Designer
Match two real impedances with an ideal quarter-wave line and calculate the required physical length.
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Open / Short Shunt Stub Tuner
Lossless single-shunt-stub match for a complex load. Returns the nearest two line positions where conductance is unity and stub lengths for the first solution.
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Differential Microstrip Impedance
Engineering approximation for edge-coupled microstrip differential impedance. Also reports the uncoupled single-ended Z0 from the existing microstrip model.
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Edge-Coupled Differential Stripline
Engineering approximation for symmetric edge-coupled stripline between ground planes.
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Coplanar Waveguide — No Back Ground
Classical infinite-substrate coplanar-waveguide approximation without a backing ground plane.
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Rectangular Waveguide TE10
Dominant-mode rectangular-waveguide calculator including cutoff, next-mode limit, guide wavelength and TE wave impedance.
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Skin Depth & Surface Resistance
Estimate conductor skin depth, RF surface resistance and strip resistance per metre.
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RF Via Inductance & Reactance
Quick via-inductance estimate for PCB grounding and RF return-path checks. Multiple identical vias are treated as ideal parallel inductors.
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Frequency ↔ Wavelength
Convert frequency and wavelength using a selectable propagation velocity factor. Edit either frequency or wavelength.
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Frequency ↔ Period ↔ Angular Frequency
Convert between frequency and period and report angular frequency.
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dB Ratio Converter
Enter dB, a power ratio, or a voltage/current ratio. The other forms update automatically.
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Free-Space Path Loss (FSPL)
Calculate isotropic free-space loss, propagation delay and wavelength from frequency and distance.
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Friis RF Link Calculator
Basic isotropic link budget including antenna gains, miscellaneous losses and receiver sensitivity margin.
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EIRP / ERP / Conducted Power
Convert transmitter conducted power, feeder loss and antenna gain into EIRP and ERP.
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Antenna Gain ↔ Effective Aperture
Convert antenna gain and effective aperture at a specified frequency. Equivalent circular-aperture diameter uses the entered aperture efficiency.
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Thermal Noise Floor — kTB
Thermal noise for a specified physical temperature and noise bandwidth. Includes noise density and equivalent 50 Ω RMS noise voltage.
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Noise Figure ↔ Noise Temperature
Convert between noise figure, linear noise factor and equivalent input noise temperature at the selected reference temperature.
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Receiver Sensitivity / MDS
Calculate receiver sensitivity from bandwidth, noise figure, required SNR and implementation/system loss.
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Doppler Shift Calculator
Convert radial velocity to RF Doppler shift, or edit Doppler shift to recover radial velocity. Positive velocity means increasing frequency.
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Mixer / LO / IF / Image Planner
Calculate both low-side and high-side LO choices and their corresponding first image frequencies.
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Frequency Accuracy — ppm ↔ Hz
Convert oscillator accuracy/tolerance between ppm and absolute frequency error; also show the resulting frequency limits.
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Phase ↔ Time Delay ↔ Path Length
Convert RF phase difference, time delay and physical path-length difference using the selected velocity factor.
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ADC Clock-Jitter SNR
Calculate the theoretical SNR limit imposed by RMS sampling-clock/aperture jitter, or solve maximum allowable jitter for a target SNR.
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Noise Figure Y-factor Measurement
Bench Y-factor measurement using spectrum-analyser HOT/COLD noise-density readings at the DUT output. Default example is a ~20 dB gain, 2 dB NF amplifier with a 5 dB ENR source. ENR is referenced to T0 = 290 K.