These unique properties were applied to significantly extending functionalities of conventional devices and systems
(e.g. in antennas4,5 and absorbers6–10) or developing new kinds of electromagnetic applications (e.g. cloaking
devices11–13, superlenses14,15 and wavefront conversion16–18). Additionally, designing these artificial structures
with nonlinear media or nonlinear circuits gave us an additional degree of freedom to control electromagnetic
properties19–22. Especially, metasurfaces were recently designed with several circuit elements including schottky
diodes so that they enabled us to sense difference in the waveforms of incoming waves or pulse widths23–25 (Fig. 1).
This new capability to distinguish different waves even at the same frequency was expected to give us another
degree of freedom to control electromagnetic waves, thereby leading to development of new kinds of microwave
devices and applications such as waveform-selective wireless communications26. However, all the past studies were
evaluated with only surface waves or free-space waves at a normal angle23,24,27, although in reality electromagnetic
waves scatter from various structures or boundaries and therefore illuminate such metasurfaces at oblique
angles. For this reason we clarify angular dependences of waveform-selective metasurfaces both numerically
and experimentally. Especially, this study focuses on two types of waveform-selective metasurfaces, specifically,
capacitor-based waveform-selective metasurfaces and inductor-based waveform-selective metasurfaces, each of
which more effectively absorbs short pulses and long pulses, respectively, at the same frequency26. This performance
remains unchanged for a wide range of incident angle but becomes reduced for a large incident angle, which
is also discussed to improve in this study. Our results demonstrated here are expected to open up possibilities to
apply the waveform selectivity for a wider range of electromagnetic applications even with angled waves.