Acoustic-Assisted Multiplexer Trap Circuit for H2 Suppression
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing radio frequency systems face challenges in suppressing harmonic distortion, particularly second-order harmonic emissions (H2), which are difficult to meet stringent system-level linearity specifications.
Innovation Solution
The implementation of an acoustic assisted trap circuit within a multiplexer, utilizing a second acoustic wave filter with an acoustic wave resonator and an impedance network, including an inductor, to trap harmonics associated with the first acoustic wave filter, thereby reducing H2 emissions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If acoustic wave filters are used in radio frequency systems, then signal filtering capability is improved, but harmonic distortion is generated
Solution Approach 1:
The patent converts the harmful harmonic distortion generated by acoustic wave filters into a beneficial feature by designing trap circuits that specifically target and suppress these harmonics. The trap circuits use resonators tuned to harmonic frequencies to create notches that reject the unwanted harmonic signals, thereby transforming the problem of harmonic generation into a solution where the filter system actively manages its own harmonic emissions.
Solution Approach 2:
The patent introduces trap circuits as intermediary components between the acoustic wave filters and the output. These trap circuits act as mediators that intercept and suppress harmonic signals before they propagate further, using resonators and matching networks to create frequency-selective rejection paths that target specific harmonic frequencies without affecting the fundamental signal.
2Reliability
If trap circuits are added to suppress harmonic distortion, then linearity specifications are improved, but device complexity increases
Solution Approach 1:
The patent merges the trap circuit functionality with the existing acoustic wave filter structure by integrating resonators and matching networks into the filter architecture. This consolidation allows the trap circuits to share physical space and electrical connections with the main filter, reducing the overall component count and interconnection complexity while maintaining effective harmonic suppression.
Solution Approach 2:
The patent designs the trap circuits to serve multiple functions: they suppress harmonic frequencies while maintaining proper impedance matching for the fundamental signal, and can be integrated with existing filter structures. The resonators are designed to provide both harmonic rejection and impedance transformation, reducing the need for separate matching components.
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 solution effectively reduces H2 emissions to levels below −90 dBc, meeting stringent system-level linearity specifications, while also minimizing additional area and component costs by integrating the inductor on the same die as the acoustic wave resonator.
Implementation Method 1
an acoustic wave resonator and an impedance network that are together configured to provide a trap for a harmonic associated with the first acoustic wave filter
Implementation Method 2
acoustic wave filters can include surface acoustic wave (SAW) filters and bulk acoustic wave (BAW) filters
Implementation Method 3
The impedance network can include an inductor. The acoustic wave resonator can be a shunt resonator that is in series with the inductor
Data Source
AI summary
Aspects of this disclosure relate to a multiplexer with an acoustic assisted trap circuit. The multiplexer includes an acoustic wave filter with an acoustic wave resonator and an impedance network that together provide a trap for a harmonic associated with another acoustic wave filter of the multiplexer. The acoustic wave filter can have an edge of a passband that is farther from the harmonic than other acoustic filters of the multiplexer.