Microwave Cavity Resonator Miniaturization via Capacitive Loading
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing microwave cavity resonators face limitations in miniaturization and mechanical/electrical stability due to the requirement of maintaining a quarter-wavelength electrical length, which restricts dimension reduction and increases production costs, and are sensitive to temperature variations.
Innovation Solution
The implementation of capacitor elements at the open end of the resonator element and on the cavity housing creates a capacitance gap, allowing the resonator element to be shortened below the quarter-wavelength physical length while maintaining the electrical length, using intermeshed or coaxially arranged cylindrical, quadratic, or rectangular capacitor elements to enhance capacitance and stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If the resonator element is shortened below quarter-wavelength physical length, then miniaturization is achieved, but the electrical length requirement cannot be met
Solution Approach 1:
The patent changes the electrical parameters by introducing capacitor elements that modify the capacitance distribution along the resonator element. This allows the physical length to be shortened while the electrical length (quarter-wavelength) is maintained through increased capacitive loading at strategic positions.
Solution Approach 2:
Capacitor elements are introduced as intermediary components between the resonator element and the surrounding cavity housing. These capacitor elements mediate the electrical field distribution, enabling the resonator to achieve the required electrical length with a shorter physical structure.
2Volume of moving object
If capacitor elements are placed close to the housing walls to increase capacitance, then miniaturization is enabled, but mechanical and electrical stability deteriorates
Solution Approach 1:
The patent applies local quality by placing capacitor elements at specific locations along the resonator element rather than uniformly distributing them. The capacitor elements are positioned at locations where they provide maximum capacitive loading while maintaining adequate spacing from the housing walls to ensure mechanical and electrical stability.
3Ease of manufacture
If the resonator element is made shorter, then production costs decrease, but the Q factor and operational stability worsen
Solution Approach 1:
Capacitor elements serve as intermediary components that enable the resonator element to be shortened without compromising the Q factor. By providing concentrated capacitive loading, these elements allow the shorter resonator to maintain the necessary electrical characteristics and energy storage capacity for high Q factor operation.
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
This design achieves a mechanically and electrically stable microwave cavity resonator with a high Q factor and reduced dimensions, insensitive to temperature variations and manufacturing tolerances, enabling low insertion loss and wide operational temperature range.
Implementation Method 1
capacitor elements at the open end of the resonator element and on the cavity housing creates a capacitance gap, allowing the resonator element to be shortened below the quarter-wavelength physical length while maintaining the electrical length
Implementation Method 2
the resonator element comprises an electrical length of a quarter wavelength at the resonant frequency of the cavity resonator
Data Source
Figure 1A~1C
Figure 2
Figure 3A~3B
AI summary
A microwave cavity resonator (1) comprises a cavity housing (10) forming a cavity (11), the cavity housing (10) comprising a first housing wall (100) and a second housing wall (101) opposite the first housing wall (100). A resonator element (12) is arranged in the cavity (11) and extends longitudinally along a longitudinal axis (L), wherein the resonator element (12) comprises, when viewed along the longitudinal axis (L), a first end (120) connected to the first housing wall (100) and a second end (121) opposite the first end (120), the second end (121) being arranged at a distance (D) from the second housing wall (101). The resonator element (12), at its second end (121), comprises at least one first capacitor element (123, 124, 125) and the cavity housing (10) comprises at least one second capacitor element (106, 107) reaching into the cavity (11) and arranged at a distance, when viewed along a direction perpendicular to the longitudinal axis (L), from the at least one first capacitor element (123, 124, 125) such that a gap (G) between the at least one first capacitor element (123, 124, 125) and the at least one second capacitor element (106, 107) is formed.