BAW Multiplexer Resonator Layout for Distortion Mode Suppression
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Solution Overview
Problem
Existing radio-frequency circuits face challenges in reducing multiple major distortion modes, leading to signal degradation, particularly in multiband and multimode communication systems like 5G-NR, where signal distortion occurs due to second-, third-, and fourth-order distortion modes.
Innovation Solution
A multiplexer design incorporating first and second filters with specific resonator configurations, including series and parallel arm resonators, utilizing bulk acoustic wave (BAW) technology to minimize unwanted waves of these distortion modes by optimizing resonator structures and electrode connections.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional filter designs are used in multiband communication systems, then device complexity is reduced, but signal distortion occurs due to second-, third-, and fourth-order distortion modes
Solution Approach 1:
The resonators are segmented into series-divided resonators (multiple resonators connected in series) and parallel-divided resonators (multiple resonators connected in parallel). This segmentation allows each resonator to handle specific frequency components, reducing distortion modes while maintaining manageable device complexity through modular architecture.
Solution Approach 2:
Different resonators are configured with specific series or parallel connections tailored to their functional requirements. Series-divided resonators are used in series arms to reduce even-order distortion, while parallel-divided resonators are used in parallel arms to reduce odd-order distortion, optimizing local signal quality for different distortion modes.
2Object-generated harmful factors
If series-divided resonators are used to reduce even-order distortion modes, then unwanted waves of second and fourth order are reduced, but device complexity increases
Solution Approach 1:
Series-divided resonators divide the series arm into multiple resonator segments connected in series. This segmentation creates multiple resonance points that selectively attenuate even-order distortion frequencies while maintaining the overall filter response, reducing harmful even-order distortion waves through distributed resonance control.
3Object-generated harmful factors
If parallel-divided resonators are used to reduce odd-order distortion modes, then unwanted waves of third order are reduced, but device complexity increases
Solution Approach 1:
Parallel-divided resonators divide the parallel arm into multiple resonator segments connected in parallel. This configuration creates multiple parallel resonance paths that selectively reject odd-order distortion frequencies while maintaining signal transmission, reducing harmful odd-order distortion waves through distributed resonance rejection.
4Adaptability or versatility
If multiple filters with different pass bands are connected via switch, then multiband support is achieved, but signal distortion increases due to distortion modes
Solution Approach 1:
The multiplexer incorporates multiple filters (first filter with first pass band, second filter with second pass band) that can be selectively connected to the common terminal through switching. Each filter is equipped with resonators configured to reduce distortion modes, enabling the system to support multiple frequency bands while maintaining signal quality across all bands through integrated distortion reduction.
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 multiplexer effectively reduces the occurrence of unwanted waves of multiple major distortion modes, enhancing signal quality and reducing signal loss in multiband and multimode communication systems.
Implementation Method 1
Each of the first series arm resonator and the first parallel arm resonator includes a first support substrate, a first bottom electrode disposed above the first support substrate, a first top electrode disposed above the first bottom electrode, and a first piezoelectric layer disposed between the first bottom electrode and the first top electrode
Data Source
AI summary
A multiplexer includes first and second filters connected to an antenna connecting terminal. The first filter includes a first series arm resonator and a first parallel arm resonator. Each of the first series arm resonator and the first parallel arm resonator includes a bottom electrode, a top electrode, and a piezoelectric layer. At least one of resonators forming the first series arm resonator and the first parallel arm resonator is constituted by plural series-divided resonators. The second filter includes plural second series arm resonators and a second parallel arm resonator. Each of the plural second series arm resonators and the second parallel arm resonator includes a bottom electrode, a top electrode, and a piezoelectric layer. Among the plural second series arm resonators, the top electrodes or the bottom electrodes of two adjacent second series arm resonators are formed by one electrode.