  We present the first experimental observation of quantized Klein tunneling in
a bounded Dirac system, implemented by a dimer chain of dielectric microwave
resonators. Both the unusual quantized levels and corresponding spinor states
hybridized from distinct particle and hole wavefunctions are measured. All
observations are in quantitative agreement with the hitherto-untested
prediction of Dirac equation. Our results make an important step to realize and
understand the particle-hole physics of Klein tunneling in bounded Dirac
systems, and also shed light on potential applications for manipulating
particle-hole hybridized spinor waves.
