Design, simulate and verify electronics in one engineering workspace.

Intuition. Freeze time and ask where the circuit settles. DC finds the equilibrium imposed by sources and nonlinear device laws.

What is computed. MAJAL/ngspice solves the nonlinear operating-point equations self-consistently. In ideal steady state a capacitor carries no DC current and an inductor is a short circuit.

Use it for. Biasing BJT/MOSF devices, checking supply current, node voltages, headroom, saturation/cutoff and dissipation before small-signal analysis.

Important limit. DC says nothing about frequency response or startup dynamics. A correct bias point does not guarantee stable dynamic behavior.

Intuition. Apply an infinitesimal sinusoidal perturbation and ask how its amplitude and phase change with frequency.

What is computed. Nonlinear devices are first biased, then linearized around that operating point. A complex linear system is solved at each frequency.

Use it for. Bode gain and phase, cutoff frequency, bandwidth, resonances and small-signal transfer functions.

Important limit. AC is a small-signal analysis. Large clipping, switching and startup behavior belong to transient/nonlinear analysis.

Intuition. Let time run and watch the circuit evolve sample by sample instead of assuming a sinusoidal steady state.

What is computed. The time-domain differential-algebraic equations are numerically integrated while nonlinear device laws are solved at each time step.

Use it for. Startup, switching, pulses, ringing, settling, oscillators, clipping and large-signal waveforms.

Important limit. Time step and stop time matter. Too coarse a step can hide fast behavior; too short a run can miss settling or low-frequency dynamics.

Intuition. Treat each RF port as a wave interface: part of an incident wave is reflected and part is transmitted to the other ports.

What is computed. MAJAL solves the frequency-domain network and reports complex Sij ratios referenced to the selected port impedances.

Use it for. S11 matching/return loss, S21 transmission or gain, multiport coupling, Touchstone networks and Smith-chart interpretation.

Important limit. An S-parameter model is tied to its linear operating condition and reference impedances. Large-signal compression requires a nonlinear workflow.

Intuition. Do the same experiment repeatedly while changing one component value, so sensitivity becomes visible instead of guessed.

What is computed. MAJAL clones the design for each requested parameter value and reruns the selected RF, DC, AC or transient analysis.

Use it for. Sensitivity, tolerance intuition, choosing useful parameter ranges and understanding non-monotonic behavior before optimization.

Important limit. A one-dimensional sweep explores only the chosen path through design space; interactions between several parameters may require a 2D map or optimization.

Intuition. Instead of manually turning knobs, define measurable engineering goals and let the search engine explore candidate component values.

What is computed. Each candidate is simulated with the required analysis domains, converted into objective metrics and scored against the user’s constraints and targets.

Use it for. Meeting gain/return-loss masks, bias constraints, transient metrics or several objectives simultaneously after sensible parameter bounds are chosen.

Important limit. Optimization does not replace engineering judgment. Unrealistic bounds, incomplete models or poorly chosen objectives can produce a mathematically valid but physically poor design.