How to read this thing
Every point in the disk is one complex reflection coefficient Γ, and simultaneously an impedance, an admittance, a VSWR, a return loss, a Q, and a position on a line. The side panel reads them all at once: that is the “N-D” in the title.
scroll zoom (the grid refines as you go, try the right edge, where infinity lives) · drag pan · click pin/unpin the probe.
/ search, try “stub”, “Hogan”, “hyperbolic”, or an impedance like 0.7+j1.5 · 1 chart · 3 Riemann sphere · h hyperbolic disc · g graph · m mechanical relabel · 0 reset.
Sphere: the 3-D Smith chart, passive charts on the upper hemisphere, active circuits (|Γ|>1) below the equator, ∞ at the south pole. Hyperbolic: the entire generalized plane, ∞ included, compactified into one disc. The probe is shared across all three chart views.
.sNp loads a Touchstone VNA export (.s1p/.s2p, MA/DB/RI formats, or drag one onto the chart): the measured reflection traces as a locus in every view. Game: random mismatched load, reach |Γ|<0.05 with series/shunt L and C, fewest elements wins.
Colors: domain of each concept (legend in the index). Palette validated for color-vision safety in both themes.
Companion to the Veritasium episode on the Smith chart. Geometry after P. H. Smith (1939); sphere extension after Müller et al. (2011).