Multiplexer Common-Line Impedance Matching Across Pass Bands
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Solution Overview
Problem
Existing multiplexers and antenna modules face deterioration in characteristics due to impedance mismatching, especially at higher frequencies where elements within the devices act as resonant elements, leading to impedance mismatching issues that are not adequately addressed in existing technologies.
Innovation Solution
The proposed solution involves a multiplexer and antenna module configuration that includes a common terminal, common line, first terminal, second terminal, first filter, and second filter, where at least one of two conditions is satisfied: in the first pass band, one impedance includes an inductive property and the other a capacitive property, and in the second pass band, one impedance includes an inductive property and the other a capacitive property.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If the frequency of input signal is increased, then the wavelength decreases and more elements can be integrated, but impedance mismatching occurs and characteristics deteriorate
Solution Approach 1:
The patent applies parameter changes by adjusting the impedance characteristics of the common line to compensate for frequency-dependent effects. Specifically, the common line is designed with a characteristic impedance that varies with frequency, and its length and impedance are optimized to provide inductive or capacitive reactance that counteracts the resonant effects of other elements at different frequency bands, thereby maintaining impedance matching across wide frequency ranges.
Solution Approach 2:
The common line serves as an intermediary element between the common terminal and the filters/radiating elements. By carefully designing the common line's impedance and length, it mediates the impedance interaction between different components, preventing harmful resonant effects and maintaining proper impedance matching across multiple frequency bands without requiring additional matching components.
2Adaptability or versatility
If multiple filters are used to achieve multiple pass bands, then frequency selectivity is improved, but device complexity increases
Solution Approach 1:
The common line performs multiple functions simultaneously: it serves as a transmission line connecting the common terminal to various filters, acts as an impedance matching element, provides frequency-dependent reactance to counteract resonant effects, and enables multiple pass bands through its interaction with different filters. This multi-functionality reduces the need for separate components and simplifies the overall device structure.
Solution Approach 2:
The patent merges the common line's transmission function with its impedance matching function. Instead of using separate transmission lines and impedance matching networks for each filter, the common line is designed to provide both functions across multiple frequency bands, thereby reducing device complexity while maintaining multiple pass bands.
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 suppresses the deterioration of characteristics in multiplexers and antenna modules due to impedance mismatching, ensuring improved performance across different frequency bands.
Implementation Method 1
any one of a first impedance of the common line alone viewed from the common terminal and a second impedance of the first filter viewed from the common connection node includes an inductive property, and the other includes a capacitive property
Data Source
AI summary
A common line is connected between a common terminal and a common connection node. A first filter has a first pass band. A second filter has a second pass band. At least one of a first condition and a second condition is satisfied. The first condition is that in the first pass band any one of a first impedance of the common line alone viewed from the common terminal (P10) and a second impedance of the first filter viewed from the common connection node includes an inductive property and the other includes a capacitive property. The second condition is that in the second pass band one of the first impedance and a third impedance of the second filter viewed from the common connection node includes an inductive property and the other includes a capacitive property.