  Amplitude-modulated (AM) leaky-wave antenna (LWA), a concept following
amplitude modulation technique from classical communications theory, is a
promising structure that enables transforming traveling wave into the radiating
wave. In this paper, we provide a different perspective based on the classical
holographic theory to gain insight into the physical mechanism of AM LWA and
design novel LWAs. In analogy to the classical optical Gabor hologram, we
demonstrate that only the amplitude variation of the traveling wave is needed
to record both the amplitude and phase information of the object wave. The
consistency between the holography theory and previous spatial spectrum
approach for explaining AM LWA operating mechanism is also demonstrated. For
validation purpose, two novel millimeter-wave (mmW) holographic AM LWAs based
on the substrate integrated inset dielectric waveguide (IDW) are designed. The
first one is for far-field high-gain applications while the second is for
near-field focusing (NFF) applications. Both simulated and measured results
demonstrate the effectiveness of the AM holography theory for AM LWAs analysis
and design.

Applied Physics;Optics