Multiband Circuit Signal Branch Integration Near-Band Rejection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing multiband circuits face challenges in being economically viable and space-efficient for signal separation across different frequency bands, with limitations in near-band rejection and transmission characteristics.
Innovation Solution
A multiband circuit design that combines two signal branches into a common path, where one branch is transmissive in a first frequency band and the other in a second frequency band, with a second circuit shunting HF signals to ground at a blocking frequency, creating a short circuit and improving near-band rejection by steepening the flank in the transfer function.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a diplexer is used for signal separation in multiband circuits, then signal separation between frequency bands is achieved, but near-band rejection is insufficient and the circuit occupies excessive space
Solution Approach 1:
The patent combines two separate filter functions into a single integrated circuit structure. The first circuit (low-pass filter) and second circuit (band-pass filter) are merged into one compact unit with shared components, replacing traditional separate diplexer components. This merging achieves improved near-band rejection while reducing the overall circuit footprint to a space-efficient design.
2Reliability
If traditional filter configurations are used, then signal transmission in specific bands is achieved, but the transmission characteristics lack sufficient selectivity and steepness
Solution Approach 1:
The patent applies local quality by designing the second circuit as a band-pass filter with specific frequency-selective characteristics that operate effectively only in the upper frequency band. This localized filter characteristic provides steep transmission flanks and high selectivity in the critical near-band region, improving transmission characteristics without requiring complex filtering across all frequency ranges.
Solution Approach 2:
The patent uses a composite filter structure combining different filter topologies - a low-pass filter section and a band-pass filter section - to achieve superior transmission characteristics. The combination of these different filter types creates steep flanks and enhanced selectivity that neither filter could achieve alone, while maintaining manageable structural complexity through integrated design.
3Ease of manufacture
If economically viable multiband circuits are designed, then cost reduction is achieved, but near-band rejection and transmission characteristics deteriorate
Solution Approach 1:
The patent achieves economic viability through multi-functionality - the integrated circuit performs multiple functions (low-pass filtering, band-pass filtering, impedance matching) within a single device structure. This eliminates the need for multiple separate components, reducing manufacturing costs while maintaining or improving near-band rejection performance through the coordinated operation of the combined filter circuits.
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 solution enhances near-band rejection and improves the transmission characteristics by creating a short circuit at the blocking frequency, allowing for efficient signal separation across multiple frequency bands in a compact and cost-effective manner.
Implementation Method 1
The second circuit comprises a second matching network (second low-pass filter) arranged on the antenna side, which are directly conductively connected to one another and to the common path
Data Source
AI summary
A multiband circuit includes a signal path comprising a first signal branch that includes a first circuit that is transmissive in a first frequency band and a second signal branch that includes a second circuit that is transmissive in a second frequency band. The first and second signal branches are combined on an antenna side into a common path.