Duo-Quad Waveguide Combiner for High-Power RF Mode Conversion
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
High-power microwave technology faces challenges in efficiently combining radio frequency (RF) power from separate waveguides into a single feed suitable for a directive antenna, particularly during the incoherent plasma oscillations of pulsed magnetrons, where spurious frequencies can disrupt the formation of the π mode, and requires a tunable frequency band with a low reflection coefficient.
Innovation Solution
A duo-quad wideband waveguide combiner is designed, featuring a circular waveguide with bifurcated waveguides that transition from rectangular to pie-slice shaped cross-sections, minimizing reflections and maintaining impedance continuity, allowing for the combination of two TE10 rectangular mode signals into a TE01 circular mode signal with high mode purity and low reflection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If radial extraction via rectangular waveguide is used from magnetron resonators, then RF power extraction efficiency is improved, but the problem of combining RF power in separate waveguides into a single feed arises
Solution Approach 1:
The patent combines multiple rectangular waveguides into a single circular waveguide feed structure. The rectangular waveguides are positioned at specific orientations (e.g., 0°, 90°, 180°, 270°) and merged into a common circular waveguide, consolidating multiple RF power paths into a single feed suitable for directive antennas.
Solution Approach 2:
The circular waveguide is segmented into multiple rectangular waveguide sections that can be independently connected to magnetron resonators. Each rectangular waveguide section maintains its own TE10 mode propagation while being part of the unified circular waveguide structure, allowing independent power extraction from multiple resonators.
2Device complexity
If conventional waveguide combining structures are used, then structure simplicity is maintained, but reflection coefficient increases over broad frequency bands
Solution Approach 1:
The waveguide combining structure is designed to be dynamically adaptive across frequency bands. The circular waveguide geometry and the arrangement of rectangular waveguide sections create a structure that naturally maintains low reflection coefficients across a broad frequency range, adapting to frequency variations without requiring active adjustment mechanisms.
Solution Approach 2:
The patent changes the waveguide mode from rectangular TE10 to circular TE01 at the combining junction. This parameter change in waveguide geometry and mode structure enables broad bandwidth operation with low reflection coefficients, as the circular waveguide can accommodate a wider frequency range compared to conventional rectangular waveguide combinations.
3Ease of manufacture
If simple waveguide transition structures are used, then manufacturing ease is improved, but mode purity degrades when transforming from rectangular TE10 to circular TE01 mode
Solution Approach 1:
The transition from rectangular to circular waveguide sections utilizes curved transitions rather than sharp corners. The circular waveguide sections are oriented at specific angles (0°, 45°, 90°, 135°) and merged smoothly into the common circular waveguide, maintaining mode purity while being manufacturable with standard precision techniques.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution effectively combines RF power with high mode purity and low reflection over a broad frequency band, suitable for high-power microwave applications, ensuring reliable pulse formation and tunability, and is suitable for high-power microwave systems.
Implementation Method 1
two waveguides, each waveguide being bifurcated at an input to the wave guide combiner... each of the bifurcated waveguides rotating to a respective one of the four quadrants about the center axis of the circular waveguide... transforming two rectangular waveguides in the TE10 rectangular mode to a single circular waveguide output in the TE01 mode
Data Source
AI summary
A duo-quad wideband wave guide combiner includes a circular waveguide having a center axis with a cross section with four quadrants; and two waveguides, each waveguide being bifurcated at an input to the wave guide combiner by a thin septum to split each of the two waveguide into two bifurcated waveguides, each of the bifurcated waveguides rotating to a respective one of the four quadrants about the center axis of the circular waveguide with converging walls terminating when a composite cross section becomes circular.