Getting started
This is a small-signal (AC) symbolic tool, not a SPICE-like simulator --
there is no DC operating point or transient analysis, and every part is already
linear: a transistor's small-signal model is drawn directly as an R/G/E
combination, not as a transistor.
Draw a circuit (or load an Example) and drop a Netname label on the
input and output nodes. Pick them in Port Configuration and H(s) appears
automatically -- there is no Analyze button, every edit re-solves.
Schematic editor
Click a palette button (or press its key) to pick up a part, click again on
the canvas to drop it, Esc to cancel. Drag to move, Ctrl+R /
Ctrl+E to rotate/mirror, double-click (or right-click) a part to
edit its name or value. The ? button on the canvas itself has
the full key list.
Port configuration & impedance
There is no source part to place -- picking a node here injects a voltage or
current source there internally (per the Voltage/Current toggle); it is never a
component on the schematic, and its own name never appears in H(s). Choosing the
same node for input and output with Current gives the driving-point
impedance directly -- or use the separate "Impedance at node" tool to get
Zin/Zout without touching the main H(s) at all (it kills the real source and
probes elsewhere on its own, one-off circuit).
Values & Plot
Type a number for any symbol to substitute it live into H(s). Once every
symbol has a value, the Bode (magnitude/phase/group delay) and Nyquist plots
follow automatically.
Approximation
Chain simplifications onto H(s) one step at a time -- a DC/HF limit,
polynomial truncation, a symbolic assumption ("gm*ro >> 1"), or a
numerical guide from the values you have entered. Compare the result against
the original with the Bode overlay.
Sensitivity
See which component matters most for a factored section's f0/Q, or for the
magnitude/phase at a chosen frequency -- results are sorted by impact, the
biggest lever first.
Save & share
Export writes a JSON file with everything: the schematic, the substituted
values, the approximation steps actually applied, and the plot/view settings.
Import restores all of it. Share Link is lighter and different: it
encodes just the circuit diagram into the page URL, nothing else and nothing
uploaded anywhere -- opening that link redraws the schematic with no file to
send.