This simulator compares a free-space reference path with a matched coaxial cable path driven by the same source. Send a continuous sinusoid or a single Gaussian RF pulse, track its arrival at each path's probe, and watch wavelength shorten in the cable when velocity factor slows propagation without changing the source frequency.
• A real-time scene of a dual-channel RF source, an ideal free-space reference lane, a cutaway matched coaxial cable (center conductor, dielectric, braid, jacket), a wavelength/distance ruler, paired measurement probes, and matched terminations with an oscilloscope comparing both delayed traces. • Nine experiment controls: common source frequency (50–500 MHz), cable velocity factor (0.4–1, fraction of c), path length (1–5 m, same physical length in both paths), peak voltage (0.2–2 V), drive signal (continuous sinusoid or single Gaussian RF pulse), pulse envelope width σ (0.5–3 ns), measurement position (0–1, fraction of path length), and show/hide toggles for traveling markers and the cable cross-section. • Live metrics: cable propagation speed, cable wavelength, reference wavelength, source period, cable end-to-end transit, reference transit, additional cable delay, cycles along the cable, cable end phase lag and both probe voltages. • Playback controls: restart animation and send RF pulse, plus standard pause/resume and speed controls. • A Curves & measurements tab with two live charts (cable propagation speed and wavelength), the full set of governing equations, and snapshot measurement readouts. • An Experiments tab with four guided fixtures (half-speed cable, send a pulse, double frequency same speed, equal-speed comparison) and a Model verification bench, plus a timestamped event log and a copyable trial report. • A Learn & assess tab with four guided lessons, a knowledge-check quiz with reset, and a written model-scope statement with a technical-background reference link.
Both channels oscillate at the same source frequency. At a fixed propagation speed, raising frequency packs more cycles into a metre, so wavelength shrinks while crest speed stays the same. The cable's velocity factor changes phase speed to v = VF·c; because frequency is conserved along the whole path, cable wavelength becomes exactly VF times the reference wavelength — this models a nondispersive matched line, not a simulated dielectric interface or impedance discontinuity.
Transit time equals path length divided by speed (τ = L/v). A continuous sine wave only reveals phase modulo a full cycle, so the displayed unwrapped phase lag is calculated from geometry rather than read directly off an ambiguous waveform; a pulse gives an unambiguous arrival-time marker instead. In this ideal nondispersive model, the pulse envelope and individual carrier crests travel at the same speed, so no pulse broadening or frequency-dependent loss is included.
The cable is matched, lossless and nondispersive with a velocity factor independent of frequency — there is no reflection, attenuation, impedance mismatch or cable heating in this model. One playback second represents 1 ns.
Wavelength halves. Since v = fλ and speed is held fixed, wavelength is inversely proportional to frequency.
No. This model changes propagation speed and therefore wavelength inside the cable, but the source frequency itself — set by the dual-channel RF source — stays exactly the same in both paths.
A continuous sine only shows phase modulo one cycle, which is ambiguous for measuring total transit time. A Gaussian pulse envelope provides a single, unambiguous arrival-time marker at each path's probe.
The cable then propagates at exactly the speed of light, matching the free-space reference path — the two traces coincide, their pulse envelopes arrive together, and the additional cable delay becomes zero.