|First example—Wave at normal incidence to flat reflector, no gap|
In this first "warm-up" example, a plane wave enters from the top of the space, and strikes a flat, perfectly reflecting surface at normal incidence. What is shown is magnitude of the E field at a plane in the middle of the volume. The incident wave interferes with the reflected wave, resulting in a standing wave. At the reflecting surface, the magnitude of the E field is always zero. The box is 4 mm high in the z direction and 6mm wide in the x direction. The frequency of the incoming wave is 150 GHz, so the box is approximately two wavelengths high. The rms field strength of the incoming wave is 1 V/m. The E field of the standing wave must always have a z dependence which varies as sin(2πz/λ).