This is a pictorial description of the hybrid time-domain simulator used to generate the results on the following pages. The simulator consists of multiple interconnected component simulators. Each component simulator analyzes a subsystem of interest and is a physics simulator on its own: The cable solver uses transmission line theory to analyze cable networks, the circuit solver uses modified nodal analysis to analyze linear and nonlinear circuits, the macromodel solver uses multi-port transfer function blocks to describe linear systems, and the integral- and differential-equation based electromagnetic solvers use Maxwell's equations to analyze radiation, scattering, and propagation effects. The solvers are connected at well-defined ports and exchange signals (fields/currents/voltages) between the subsystems at each time step.
The simulator operation is analogous to that of the human body; just like body parts, each component (i) is specialized, (ii) is often used (effectively or ineffectively) in place of one another, and (iii) can best perform certain tasks only when used simultaneously with other components:
(i) Each component is specialized (is much more efficient than other components) for doing certain tasks, e.g., as it is more effective to walk on your feet than on your hands, it is more effective to analyze cables using transmission line theory than Maxwell's equations in their full form.
(ii) Components can be used in place of one another, e.g., as it might not matter whether you use your arms or feet to throw/hit a ball as long as the ball gets to its destination, it might not matter which component is used to analyze a circuit as long as the results are accurate. This is often stated as 'everyone has their favorite hammer'. Similarly, just as some walk on their hands and open doors with their feet, some use circuit solvers to analyze cables or antennas. This is often stated as 'a hammer is not good for everything'.
(iii) Certain tasks are best performed using multiple components at the same time, e.g., as it is more effective to swim using both your arms and feet simultaneously, it is more effective to use multiple simulators simultaneously to analyze complex phenomena, i.e., hybrid simulators enable certain simulations that are otherwise impossible.
