Figure 1. a) Example architecture of an impulse ranging radar; b) basic concept of chaotic communication.

Figure 2. a) Nonlinear transmission line (NLTL); b) alternative form of the NLTL; c) a general soliton waveform on an infinitely long NLTL; (d) mono-pulse case; e) illustration of solitons' amplitude-dependent speed and nonlinear collision; f) hypothetical transient soliton-forming processes on the NLTL.

Figure 3. a) Electrical soliton oscillator; b) ring NLTL and the first three soliton circulation modes; c) traditional approach to generate electrical solitons using an NLTL.

Figure 4. a) Transfer function of a standard voltage-limiting amplifier; b) simulated unstable oscillation; c) impact of signal clipping and soliton dynamics; d) simulated power spectral density of the unstable oscillation signal with a weak nonlinearity of the NLTL; e) simulated power spectral density of the unstable oscillation signal with a strong nonlinearity of the NLTL.

Figure 5. a) Nonlinear transfer curve of the saturating amplifier. In the initial startup, bias point A lies in the gain region. Increased DC component during the transient (Fig. 5b) is used to lower bias of the amplifier, leading to a steady-state bias B; b) DC component of the amplifier output increases as the oscillation grows and forms into a soliton pulse train, c) example oscillator implementation.

Figure 6. a) First soliton oscillator prototype, and a measured steady state stable periodic train of soliton pulses; b) second soliton oscillator prototype and a measured steady-state stable periodic train of soliton pulses; c) third chip-scale soliton oscillator prototype with a measured steady-state stable periodic train of solitons; d) measured initial startup transient from the first prototype of Fig. 6a.