Design and testing of multi-standard waveguide couplers

Area of Science:

• Electromagnetics and Waveguide Technology
• Microwave Engineering
• Plasma Physics Instrumentation

Background:

• Traditional waveguides are optimized for single-frequency operation, limiting their use in multi-band applications.
• Integrating multiple frequency bands, such as X-band and S-band, into a single waveguide is challenging.
• Applications like plasma diagnostics require simultaneous multi-band frequency access within a single waveguide structure.

Purpose of the Study:

• To design and present two novel coupler types for integrating X-band frequencies into an S-band waveguide system.
• To achieve a large coupling coefficient (< -10 dB) and a small reflection coefficient (> -10 dB) at 11 GHz.
• To provide a detailed procedure for design, parameter optimization, and initial value estimation for custom waveguide structures.

Main Methods:

• Development of two distinct coupler designs for multi-band waveguide integration.
• Parameter optimization and initial value estimation using simulation tools.
• Fabrication of custom waveguide structures.
• Experimental validation using an Agilent E8364B PNA network analyzer.

Main Results:

• The designed couplers demonstrated a large coupling coefficient and small reflection coefficient at the target frequency.
• Experimental results showed reasonable agreement with simulated performance across the frequency range of interest.
• The proposed couplers successfully enable the integration of X-band frequencies into an S-band system.

Conclusions:

• The presented waveguide coupler designs are effective for multi-band frequency integration.
• The developed techniques facilitate the implementation of complex multi-frequency systems within a single waveguide.
• This work contributes to advancing waveguide technology for applications requiring simultaneous operation across different frequency bands.