amplitude antinode carrier carrier wave crest de Broglie wave diffraction electric wave electromagnetic radiation electromagnetic wave frequency frequency band frequency spectrum ground wave guided wave hertzian wave high-frequency wave in phase interference light long wave longitudinal wave low-frequency wave mechanical wave microwave node out of phase period periodic wave radio wave ray reinforcement resonance resonance frequency seismic wave shock wave shortwave sky wave sound wave surface wave tidal wave transverse wave trough wave wave equation wave motion wave number