Duplexer Wiring Overlap Structure for Filter Isolation
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Solution Overview
Problem
Existing duplexers in communication devices face challenges in improving isolation characteristics between transmit and receive filters, leading to signal leakage and reduced flexibility in wiring arrangements.
Innovation Solution
The implementation of a duplexer design that includes open and short stubs electromagnetically coupled with each other, allowing for improved isolation characteristics between filter circuits while increasing the flexibility in wiring arrangements by adjusting the self-inductance values and overlapping amounts of these stubs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the first and second wirings are arranged in parallel to improve isolation characteristics, then the isolation between transmit and receive filters is improved, but the flexibility in wiring arrangement is reduced
Solution Approach 1:
The patent transitions from planar parallel wiring arrangement to a three-dimensional overlapping configuration where the first wiring and second wiring are positioned on different layers or planes. This spatial dimensionality change enables electromagnetic coupling for improved isolation while allowing independent routing paths that maintain design flexibility.
Solution Approach 2:
The patent introduces a ground wiring as an intermediary element between the first wiring and second wiring. This ground wiring serves as a mediator that enhances electromagnetic coupling and isolation characteristics while providing a reference potential that enables flexible arrangement of the signal wirings without compromising performance.
2Reliability
If the overlap amount between first and second wirings is increased to improve isolation, then the isolation characteristics are enhanced, but the wiring layout complexity increases
Solution Approach 1:
The patent divides the wiring structure into distinct segmented portions - the first wiring, the second wiring, and the ground wiring - that can be independently designed and optimized. This segmentation allows the overlap amount to be controlled in specific regions while keeping other portions simple, thereby reducing overall layout complexity while maintaining isolation performance.
Solution Approach 2:
The patent applies electromagnetic coupling selectively in specific local regions where the first and second wirings overlap, rather than maintaining uniform coupling throughout the entire wiring length. This local quality approach concentrates the isolation enhancement where needed while simplifying the wiring arrangement in non-critical regions.
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 configuration effectively enhances the isolation characteristics between filter circuits, reducing signal leakage and allowing for more flexible and efficient design of duplexer structures without significantly affecting impedance characteristics.
Implementation Method 1
The first and second wirings are electromagnetically coupled with each other
Data Source
AI summary
A duplexer includes first and second filter circuits and first and second wirings. The first filter circuit allows a signal of a first frequency band to pass therethrough between a first terminal and a common terminal and includes a first resonator which is connected at one end to a line disposed between the first terminal and the common terminal to branch off from the line. The second filter circuit allows a signal of a second frequency band, which is different from the first frequency band, to pass therethrough between a second terminal and the common terminal. The first wiring is connected at one end to the common terminal and is opened at the other end. The second wiring is connected at one end to the other end of the first resonator and is grounded at the other end. The first wiring is electromagnetically coupled with second wiring.