Signal & RF Formulas
RF formulas connect frequency, wavelength, and impedance for transmission lines and antennas. These calculators help you size matching networks, estimate antenna dimensions, and reason about high-frequency layout. They are essential for wireless, transmission-line, and microwave work.
Signal & RF Formula Calculators
- Wavelength λ = c / f
- Free Space Path Loss FSPL = 20log(d) + 20log(f) + const
- Signal-to-Noise Ratio SNR = 10 × log₁₀(Ps/Pn)
- Nyquist Sampling Rate fs_min = 2 × fmax
- Link Budget Prx = Ptx + Gtx − Ltx − FSPL + Grx − Lrx
- Antenna Gain G = 10 × log₁₀(4πAe/λ²)
- Skin Depth δ = 1 / √(πfμσ)
- Friis Noise Figure (3-stage) NFtotal = NF1 + (NF2−1)/G1 + (NF3−1)/(G1×G2)
- Thermal Noise Power Pn = k × T × BW
- VSWR VSWR = (1 + |Γ|) / (1 − |Γ|)
- Return Loss RL = −20 × log10(|Γ|)
- Effective Radiated Power ERP = Ptx × Gt
- Third-Order Intercept Point OIP3 = Pout + (IIP3 − Pin) / 2
- Equivalent Noise Temperature Te = T0 × (NF − 1)
- Group Delay (Approximation) τg ≈ 1 / (2π × BW)
- Reflection Coefficient Γ = (ZL − Z0) / (ZL + Z0)
- Insertion Loss from S21 IL = −20 × log10(|S21|)
- Doppler Frequency Shift Δf = fc × v / c
- Radar Range Equation Rmax = (Pt×Gt×Gr×λ²×σ / ((4π)³×Smin))^0.25
- Carson's Rule FM Bandwidth BW = 2 × (Δf + fm)
- Spurious-Free Dynamic Range SFDR = 20 · log10(Vsignal / Vspur)
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