Resonator Filter Module With Variable Pole Harmonic Suppression
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing filters, particularly those used in mobile communication devices and chemical/biological devices, face challenges in effectively suppressing harmonics, which lead to noise and degrade filtering performance due to their compact and lightweight designs.
Innovation Solution
The implementation of a filter design that includes series resonators connected in series, shunt resonators, and a variable capacitor configured to form a pole that suppresses harmonics, where the frequency of the pole is adjustable by varying the capacitance of the variable capacitor, formed by a wiring electrode and dummy connection pads with ground potential, to optimize harmonic suppression.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Weight of moving object
If filters are designed to be compact and lightweight, then device size and weight are reduced, but harmonic suppression performance deteriorates
Solution Approach 1:
The patent embeds dummy connection pads within the filter structure, nesting them below the substrate. These nested dummy pads create additional capacitance that forms poles for harmonic suppression without increasing the external dimensions of the filter, thus maintaining compact size while improving harmonic suppression performance
Solution Approach 2:
The patent utilizes the vertical dimension by placing dummy connection pads below the substrate rather than expanding horizontally. This dimensional approach allows additional harmonic suppression elements to be incorporated without increasing the filter's footprint area, resolving the contradiction between compact size and harmonic suppression capability
2Volume of moving object
If filters are designed to be compact and lightweight, then device size and weight are reduced, but filtering performance deteriorates
Solution Approach 1:
The dummy connection pads are nested within the existing filter structure below the substrate, utilizing unused space. This nesting approach adds filtering functionality through additional poles without increasing the overall filter volume, thus maintaining compact design while improving filtering performance
Solution Approach 2:
The patent changes the electrical parameters of the filter by introducing variable capacitance through dummy connection pads with different ground potential connections. By adjusting the number of dummy pads connected to ground, the pole frequencies are tuned to optimize harmonic suppression, thereby improving filtering performance within the same volume
3Object-generated harmful factors
If dummy connection pads are added to form variable capacitor, then harmonic suppression is improved, but device complexity increases
Solution Approach 1:
The dummy connection pads serve multiple functions: they act as electrical connections, create variable capacitance, and form poles for harmonic suppression. This multi-functionality approach improves harmonic suppression without proportionally increasing device complexity, as the same structural elements perform multiple roles
Solution Approach 2:
The patent uses simplified dummy connection pads that replicate the functionality of actual connection pads but without full electrical connections. These copied elements provide the necessary capacitance for harmonic suppression while being simpler in structure, thus improving harmonic suppression with minimal increase in complexity
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 design effectively adjusts the frequency of the pole to suppress harmonics, thereby improving filtering characteristics and reducing noise, enhancing the performance of compact lightweight filters used in mobile communication and other devices.
Implementation Method 1
an electric field is induced in the piezoelectric layer by electrical energy applied to the first and second electrodes, a piezoelectric phenomenon occurs in the piezoelectric layer by the induced electric field, and thus the resonator vibrates in a predetermined direction
Implementation Method 2
a variable capacitor connected to a second node between some of the series resonators, and forming a pole configured to suppress harmonics
Implementation Method 3
The variable capacitor may be formed by a wiring electrode corresponding to the second node and a dummy connection pad provided below the wiring electrode
Data Source
AI summary
A filter includes: series resonators connected to each other in series; shunt resonators connected to first nodes between some of the series resonators; and a variable capacitor connected to a second node between some of the series resonators, and forming a pole configured to suppress harmonics.