Snow Echo

Snow Echo turns your iPhone into a complete antenna design workbench. Specify a frequency band, choose an antenna type, and the physics engine solves everything in real time: the current distribution on every element, the full three-dimensional radiation pattern, feedpoint impedance, and SWR across the entire band.

Design half-wave dipoles, folded dipoles, Yagi-Uda arrays up to seven elements, quarter-wave ground planes, and small magnetic loops. The 3D far-field pattern rotates and zooms so you can read gain, front-to-back ratio, and beamwidth from any angle. Switch to E-plane and H-plane cuts for a precise polar view with half-power points and side-lobe level called out on the curve.

Match your antenna to 50 ohms using a built-in L-network, hairpin, or quarter-wave transformer. The Smith chart traces the full frequency sweep so you can see exactly where your design sits on the impedance plane. Feedline loss accounts for both cable attenuation and the additional power penalty that mismatch causes -- the figure most calculators leave out.

When you are ready to build, the cut sheet gives every element length and boom position to the correct tolerance for your band, and exports directly to your photo library. Log your field measurements, compare predicted SWR against what your analyser reads, and track solver accuracy across every build. A built-in Learn section explains the physics behind each result: why a reflector is longer than the driven element, what a hairpin actually does, and where the induced-EMF model reaches its limits.

Snow Echo works entirely offline. No account, no subscription, no data ever leaves your device.