Multiband Wave Separator Impedance Matching Across Common Terminal
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Solution Overview
Problem
Existing wave separator configurations with multiple duplexers face challenges in achieving good impedance matching, leading to increased bandpass loss and return loss due to optimized duplexer-specific impedance matching.
Innovation Solution
A wave separator design incorporating n number of band pass filters with a common terminal, where specific susceptance value configurations for adjacent filters ensure optimal impedance matching, utilizing series and parallel arm resonators to adjust capacitance and maintain matching without external circuits, and embedding matching circuits within a multilayer substrate to reduce size and loss.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If multiple duplexers with different frequency bands are connected to a common antenna terminal to configure a multiplexer or wave separator, then multi-band and multi-mode compliance is achieved, but impedance matching deteriorates leading to increased bandpass loss and return loss
Solution Approach 1:
The patent applies local quality by configuring specific susceptance values for different band pass filters based on their position (highest side or lowest side) and their frequency characteristics. Each filter's susceptance is locally optimized according to its specific frequency band and position in the cascade, rather than applying a uniform matching approach to all filters. This localized optimization resolves the impedance matching deterioration while maintaining multi-band compliance.
Solution Approach 2:
The patent changes the susceptance parameter of band pass filters to specific configured values based on their center frequency and position. By adjusting the susceptance parameter B(1) for the first band pass filter and B(k) for other filters according to the formulas provided, the patent achieves improved impedance matching across all frequency bands, thereby reducing bandpass loss and return loss while maintaining multi-band adaptability.
2Reliability
If duplexer-specific impedance matching is optimized, then individual duplexer performance is improved, but common terminal impedance matching deteriorates when connected to form a multiplexer
Solution Approach 1:
The patent achieves universality by designing a common terminal configuration that serves multiple band pass filters with different frequency bands simultaneously. The first band pass filter is configured with specific susceptance values that enable it to work effectively with the common terminal across multiple frequency bands, allowing the system to maintain good impedance matching for all connected duplexers rather than optimizing for individual duplexers separately.
Solution Approach 2:
The patent changes the susceptance parameters of the band pass filters to achieve common terminal impedance matching. By setting B(1) and B(k) according to the specified formulas based on center frequencies f(1) and f(k), the system achieves improved impedance matching at the common terminal while maintaining the reliability of individual duplexer performance across all frequency bands.
Data Source
AI summary
A wave separator includes an n number (n being a natural number of 3 or larger) of band pass filters having an n number or larger of mutually different pass bands, and a common terminal. For a first of the band pass filters that is one of a band pass filter having a center frequency of a pass band at a lowest side and a band pass filter having a center frequency of a pass band at a highest side and that has a larger or equal difference in a center frequency of a pass band from an adjacent band pass filter as compared with the other band pass filter satisfies a predetermined configuration for a second band pass filter having a pass band adjacent to the first band pass filter.