Dolph–Chebyshev Antenna Array Calculator
Excitation weights, beamwidth, directivity and sidelobe level of a Dolph–Chebyshev linear array with equal sidelobes. Supports beam steering.
How to use the Dolph–Chebyshev Antenna Array Calculator
- Enter or select: Number of elements N, Sidelobe level (below main beam), Element spacing d, Beam direction θ₀ (90° = broadside).
- The results (Element currents (normalised to the largest = 1), Relative to centre, in dB, Main-to-sidelobe ratio R₀, Chebyshev argument x₀, Directivity, Half-power beamwidth, Uniform-array beamwidth (same N, d), First-null beamwidth, Measured sidelobe level, Grating lobes, Pattern vs. angle from the array axis) are calculated instantly as you type.
- Use “Copy link” to share the calculation with the same input values.
Formula
- R₀ = 10^(SLL/20), x₀ = cosh[ acosh(R₀) / (N − 1) ]
- AF(ψ) = T_(N−1)(x₀ cos(ψ/2)) / R₀, ψ = kd(cosθ − cosθ₀)
- Weights = inverse DFT of AF samples at ψ = 2πm/N
About this tool
The Dolph–Chebyshev taper gives the narrowest main beam for a specified, uniform sidelobe level. Directivity assumes isotropic elements and is computed from the exact pattern; angles are measured from the array axis, so 90° is broadside.