Dielectric Waveguide with Local Metallization for THz Propagation

The patent replaces mechanical hollow waveguide structures with dielectric waveguide structures. The dielectric waveguide uses refractive index differences to guide THz waves through total internal reflection, eliminating the mechanical metal walls that cause losses through skin effect and surface roughness. This substitution of mechanical guidance with dielectric-based guidance resolves the contradiction by achieving reliable wave propagation without the frequency-dependent losses of metallic structures.

The patent employs composite dielectric structures with specific refractive index profiles to guide THz waves. By using materials with appropriate dielectric properties and creating layered or structured dielectric compositions, the waveguide achieves low-loss propagation. The composite dielectric structure allows mode confinement without the harmful interactions between THz waves and metal surfaces, thereby reducing energy loss while maintaining propagation reliability.

The patent replaces mechanical milling processes with lithographic fabrication methods. Instead of mechanically cutting metal blocks, the dielectric waveguide structures are patterned using photolithography and other semiconductor manufacturing techniques. This substitution enables scalable production, as lithography can be easily adapted to batch processing and high-volume manufacturing, thereby improving both ease of manufacture and productivity.

The patent changes the fundamental manufacturing parameters from mechanical dimensions (milling depths, tool paths) to optical parameters (photomask patterns, exposure doses, development times). This parameter transformation allows the use of established semiconductor fabrication processes that are highly scalable and cost-effective, resolving the contradiction between ease of manufacture and manufacturing scalability.

The patent replaces mechanical milling with lithographic patterning, which operates at a different scale and precision regime. Lithography can achieve feature sizes well below the THz wavelength using optical proximity effects and advanced patterning techniques, without requiring the absolute precision of mechanical milling. This substitution resolves the contradiction by enabling small dimensions at high frequencies without proportionally increasing manufacturing difficulty.

The patent uses photomask patterns as templates to copy the desired waveguide geometry. The lithographic process creates accurate replicas of the designed structure through photoresist patterning, ensuring dimensional fidelity without requiring direct mechanical measurement and adjustment. This copying approach maintains manufacturing precision even at the small dimensions required for high-frequency operation.

The patent segments the metallization into localized functional elements rather than continuous structures. Metallic components are placed only where specific functions are needed (such as antennas, couplers, or active devices), with metallization-free sections allowing low-loss THz wave propagation. This segmentation resolves the contradiction by providing necessary functionalization while minimizing the impact on wave propagation losses.

The patent applies metallization with local quality, where the presence and properties of metal are optimized for specific locations along the waveguide. Areas requiring interaction with THz waves (such as radiation or coupling points) have localized metallization, while propagation sections remain metallization-free to minimize losses. This local differentiation resolves the contradiction between adaptability and energy loss.