Examples
These recipes model complete devices. Start with the quickstart for a small first calculation. Each recipe lists its dependencies and draws its circuit: [x] is the component named x in the code, || joins components in parallel, and node 0 is ground.
| Example | What it calculates |
|---|---|
| Josephson parametric amplifier (JPA) | The reflection gain of a current-pumped JPA, against WRspice |
| JPA with a frequency dependent environmental impedance | The same JPA through a cable from a mismatched source, the pump-off reflection against a closed form |
| Multi-tone Fourier grids | The retained modes and evaluation grids of one, two and three pump tones, and their refinement |
| Double-pumped JPA | The gain between two pump tones, against WRspice |
| Flux-pumped JPA | Three-wave mixing in a flux-biased SQUID, against WRspice, and the resonance against the bias |
| SNAIL parametric amplifier | Pump-on and pump-off gain near a Kerr-free point, against WRspice |
| Josephson traveling wave parametric amplifier (JTWPA) | Gain, idlers, quantum efficiency and commutator of a resonantly phase-matched line, the pump-off line against the chain matrices of its cells |
| Floquet JTWPA | A tapered line, lossless and with dielectric loss, the pump-off line against the chain matrices of its cells |
| Impedance-engineered JPA | A snake amplifier built from nested subcircuits, signal and idler in power units, the pump-off reflection against a closed form |
| Design parameter sensitivities | Total and frozen-pump derivatives against finite differences, as gain derivatives |
| Sensitivity to frequency dependent scattering parameters | The derivative of a reflection phase against the round-trip propagation phase |
| Direct current | Static flux and average voltage, a current source's sign, and a biased junction in time |
| Pumped finite-window noise | The gain and quantum noise of a pumped amplifier in a finite time window |
| Fit a pumped amplifier | A causal fit of a pumped JPA's conversion and noise, measured in time against the circuit |
| Pulsed Josephson line | Ten pulsed signals through a Josephson line in time |
| Transient WRspice comparison | A JPA in time against WRspice |
The stability guide works through a JPA, mode tracking across a sweep, a traveling-wave amplifier's spatial mode profile and a delay circuit, telling an operating point that converged from one that is dynamically stable. The transient guide solves a circuit in time and differentiates its response, the quantum noise guide measures the vacuum and thermal noise of a passive two-port, and the scattering guide fits scattering data and simulates the result.