Microwave Structures: Match Technology to Its Description List I A. Integrated finline B. Dielectric-loaded waveguide C. Ridge waveguide List II 1. Planar slotline-like transmission structure realized inside a waveguide or between substrate-loaded plates; compatible with MMIC integration 2. Conventional metallic waveguide whose interior is partially or fully filled with dielectric to reduce size or shift cutoff 3. Rectangular waveguide modified by one or two conductive ridges to lower cutoff and broaden bandwidth

Introduction / Context:
Modern microwave hardware uses several waveguide-derived structures to achieve compact, broadband, and integrable circuits. Understanding what each structure does and how it is physically realized helps engineers choose the right medium for filters, couplers, and transitions.

Given Data / Assumptions:

• A: Integrated finline (planar finline/slotline realized with dielectric substrates).
• B: Dielectric-loaded waveguide (metal guide with dielectric filling).
• C: Ridge waveguide (conductive ridges inside a rectangular guide).

Concept / Approach:

Integrated finline places a thin dielectric (often with metallization) inside a waveguide to implement slotline-like circuits, enabling MMIC-compatible transitions. Dielectric-loaded waveguides replace air with a dielectric to reduce physical size and modify dispersion. Ridge waveguides insert ridges to concentrate electric fields, thus increasing effective capacitance, lowering cutoff, and expanding bandwidth at a given outer size.

Step-by-Step Solution:

Verification / Alternative check:

Common applications confirm these roles: finline transitions to microstrip, dielectric loading for compact filters, ridge guides for wideband components.

Why Other Options Are Wrong:

Any other pairing mixes distinct physical mechanisms: dielectric loading is not the same as adding ridges, and finline is not simply a ridge or fill.

Common Pitfalls:

Confusing finline (slotline behavior) with microstrip, or assuming dielectric loading and ridging are interchangeable techniques.

Final Answer:

A-1, B-2, C-3