Series LC Band-Pass Filter for High Stop-Band Attenuation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional band-pass filters require a large number of devices to achieve minimal zero performance, which is inefficient in terms of circuit size and design complexity.
Innovation Solution
The implementation of series LC resonators in band-pass filters, where inductors and capacitors are coupled in series to provide zeroes in the output response, allowing for improved stop-band attenuation with a minimal number of passive components.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional band-pass filter designs are used to achieve minimal zero performance, then the filter can provide basic frequency selection, but the circuit requires a large number of devices resulting in increased circuit size and design complexity
Solution Approach 1:
The patent combines the zero-providing function and filtering function into a single integrated structure. The series LC resonator is configured such that its parallel resonance frequency provides a zero in the transfer function while simultaneously providing frequency selectivity. This merging of functions reduces the total number of devices compared to conventional designs that require separate components for zero generation and filtering.
Solution Approach 2:
The series LC resonator serves multiple functions: it provides frequency selection through its series resonance frequency, generates a zero in the transfer function through its parallel resonance frequency, and enables impedance matching. This multi-functionality allows a single component to replace what would traditionally require multiple separate devices, thereby reducing overall circuit complexity.
2Reliability
If conventional band-pass filter designs are used, then the filter can provide basic frequency selection, but the circuit occupies a large area resulting in increased circuit footprint
Solution Approach 1:
The series LC resonator merges frequency selection and zero generation into a single compact structure. By configuring the resonator such that its parallel resonance frequency coincides with a desired zero frequency, the patent eliminates the need for additional components that would otherwise be required to generate zeros, thereby reducing the overall circuit footprint.
Solution Approach 2:
The patent utilizes parameter optimization by adjusting the L and C values of the resonator to achieve desired frequency characteristics. By carefully selecting the resonant frequencies of the series LC resonator, the design achieves multiple zeroes and improved stop-band attenuation with minimal components, reducing the area required for implementation.
3Device complexity
If series LC resonators are used to provide zeroes in the output response, then high stop-band attenuation is achieved with minimal passive components, but the design requires precise frequency tuning
Solution Approach 1:
The patent employs parameter optimization by adjusting the L and C values of the series LC resonator to achieve desired zero frequencies. The design leverages the relationship between component values and resonant frequencies, allowing precise frequency placement through component selection. This approach enables accurate frequency tuning while maintaining a minimal component count.
Solution Approach 2:
The series LC resonator inherently provides the zero-generating function through its natural resonance characteristics. By configuring the resonator's parallel resonance frequency to match the desired zero frequency, the circuit self-generates the required frequency response characteristics without requiring additional active tuning elements or complex control mechanisms.
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 enables high stop-band attenuation with a small circuit footprint, achieving multiple zeroes using fewer components and allowing for adjustable frequency response and impedance matching.
Implementation Method 1
inductors and capacitors are coupled in series to provide series inductor/capacitor (LC) resonators that provide zeroes in an output response of the filter
Data Source
AI summary
A band-pass filter includes an input node coupled to receive an oscillating input signal, an output node, and a first LC resonator coupled to a first node coupled between the input node and the output node and to a first power supply node coupled to provide a first voltage. The first LC resonator includes a first capacitor, and a first inductor coupled in series with the first capacitor. The output node is coupled to output a filtered response signal that includes at least one zero based on the oscillating input signal and the first LC resonator.