Multilayer Band Pass Filter Spurious Signal Suppression
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Solution Overview
Problem
Multilayer band pass filters generate spurious signals due to self-resonance of capacitor electrodes, leading to decreased impedance and unwanted high-frequency signals.
Innovation Solution
The electronic component incorporates a multilayer body with a ring-shaped LC parallel resonator and a ground conductor layer positioned to face the capacitor conductor layers, effectively redirecting self-resonance signals to a ground conductor, thereby reducing or preventing spurious signal generation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If the loop surfaces of LC parallel resonators are superposed with one another to increase coupling between inductor electrodes, then the bandwidth is widened, but self-resonance of capacitor electrodes is generated causing spurious signals
Solution Approach 1:
A ground conductor layer is introduced as an intermediary between the capacitor electrodes and the signal path. This ground layer acts as a mediator that provides a controlled impedance path for self-resonance currents, preventing them from coupling into the signal path and generating spurious signals while allowing the inductor loops to maintain their superposed configuration for broadband operation
Solution Approach 2:
The self-resonance phenomenon, which was previously harmful and caused spurious signals, is converted into a beneficial effect by providing a dedicated ground conductor path. The self-resonance currents are now channeled through the ground layer, transforming the harmful radiation and coupling into a controlled return path that actually improves filter performance by defining a clear signal ground reference
2Object-affected harmful factors
If self-resonance of capacitor electrodes is generated, then the impedance of the filter is decreased at the self-resonance frequency, but spurious signals are generated in the high frequency band
Solution Approach 1:
The harmful effect of self-resonance is extracted and isolated from the main signal path by providing a dedicated ground conductor layer. This separates the self-resonance phenomenon into its own controlled domain, allowing the signal path to maintain high impedance at spurious frequencies while the ground layer handles the self-resonance currents, preventing them from affecting the signal bandwidth
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 significantly reduces or eliminates spurious signals in the predetermined frequency band by ensuring self-resonance signals are directed to a ground conductor, enhancing the filter's performance by lowering the frequency of the attenuation pole and steepening attenuation on the high-frequency side.
Implementation Method 1
a first capacitor conductor layer (30a) and a second ground conductor layer (34) which faces the first capacitor conductor layer (30a) with one of the plurality of insulating layers (18g) therebetween
Implementation Method 2
Each of the LC parallel resonators includes capacitor electrodes and an inductor electrode. The inductor electrode is formed in the shape of a loop.
Implementation Method 3
The loop surfaces of the LC parallel resonators are superposed with one another. In such multilayer band pass filters described above, since the loop surfaces are superposed with one another, the degree of coupling between the inductor electrodes of the LC parallel resonators neighboring each other can be increased
Data Source
AI summary
An electronic component includes a multilayer body including a plurality of insulating layers stacked on top of one another. An LC parallel resonator is provided in the multilayer body, includes a coil and a capacitor, and has a ring shape when viewed in plan in the x-axis direction. The capacitor includes a capacitor conductor layer connected to one end of the coil and a resonant ground conductor layer that is connected to the other end of the coil and that is provided on the positive z-axis direction side of the capacitor conductor layer. The resonant ground conductor layer faces the capacitor conductor layer with one of the plurality of insulating layers therebetween. An outer electrode is provided on the negative z-axis direction side of the LC parallel resonator and faces the capacitor conductor layer with one of the plurality of insulating layers therebetween.