Animate Amplitude-Modulated Leaky-Wave Antennas for Unidirectional Frequency Conversion

The amplitude-modulated leaky-wave antenna (AM LWA) is a promising structure that utilizes the principles of amplitude modulation, a concept derived from classical communications theory. This innovative design allows for the conversion of traveling waves into radiating waves. This paper extends the previous stationary AM LWA into the concept of animate amplitude-modulated leaky-wave antenna (AAM LWA), where the envelope is also propagating along the waveguide. It is demonstrated that the AAM LWA enables simultaneous frequency translation and radiation in free space. As a proof-of-concept example, we designed an AAM LWA prototype with periodic meta-atoms on the top surface of a substrate-integrated waveguide at 22.5 GHz. An equivalent animate amplitude envelope can be formed along the waveguiding structure by properly loading the ON-OFF space-time sequence to modulate the LWA spatiotemporally. Experiment results demonstrate the theory and design of the proposed AAM LWA.