Filter Arrangement With Common Outer Conductor
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Solution Overview
Problem
Existing filter arrangements, particularly in mobile telecommunications, are tolerance-sensitive and difficult to optimally adjust due to their construction using separate cable impedances and solder connectors, limiting their ability to achieve desired electrical characteristics and frequency decoupling.
Innovation Solution
A trap circuit filter design where stub lines branch off from the HF main line and share a common outer conductor, allowing for adjustable impedance by varying the distance and width of the stub lines, enabling flexible frequency adaptation and increased transmission bands without separate outer conductors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If separate cable impedances and solder connectors are used to construct trap circuit filters, then the filter can be assembled with discrete components, but the filter becomes tolerance-sensitive and difficult to optimally adjust
Solution Approach 1:
The patent combines the HF main line and stub lines into a single coaxial cable structure, eliminating the need for separate cable assemblies and solder connectors. This integration removes the interfaces between discrete components, thereby eliminating the tolerance accumulation and sensitivity issues associated with multiple connection points and impedance mismatches at joints.
Solution Approach 2:
The patent extracts and eliminates the solder connectors and separate cable assemblies from the filter construction. By removing these discrete intermediate components, the design achieves direct electrical contact between the HF main line and stub lines, eliminating the tolerance-sensitive interfaces that characterized previous designs.
2Adaptability or versatility
If separate cable impedances and solder connectors are used, then the filter can be constructed with standard components, but the filter cannot be optimally adjusted to achieve desired electrical characteristics
Solution Approach 1:
The patent implements adjustable electrical contact points between the HF main line and stub lines, allowing the filter characteristics to be dynamically tuned during assembly or operation. This enables optimal adjustment of the stop frequency and attenuation levels by varying the contact position, providing adaptability that was impossible with fixed solder connector designs.
3Shape
If microstrip stub lines are used on a printed circuit board, then the filter can be constructed in a planar format, but the filter requires direct cooperation with an outer conductor surface
Solution Approach 1:
The patent merges the advantages of coaxial cable construction with the simplicity of planar layouts by using a single coaxial cable that inherently provides both the HF main line and the outer conductor. The stub lines are formed as simple conductive elements within the same cable structure, eliminating the need for separate outer conductor surfaces and complex microstrip configurations.
4Object-affected harmful factors
If coaxial cables with separate outer conductors are used for stub lines, then the filter can be constructed with shielded lines, but the filter becomes very tolerance-sensitive
Solution Approach 1:
The patent combines the HF main line and stub lines into a single coaxial cable structure with a common outer conductor. This integration eliminates the multiple interfaces and impedance discontinuities that occur when using separate coaxial cables for each stub line, thereby removing the tolerance sensitivity while maintaining the radiation shielding benefits of coaxial construction.
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 filter achieves high stop-band attenuation, low radiation sensitivity, and compact configuration with reduced manufacturing tolerances, suitable for high HF outputs and direct current signals, while allowing for easy adjustment and production with minimal space requirements.
Implementation Method 1
arranged in a common outer conductor arrangement which jointly surrounds the signalling line and the one or more stub lines
Implementation Method 2
stub lines which branch off from an HF signal-transmitting main line... achieve, for example a decoupling of approximately 50 dB between the frequency bands
Data Source
AI summary
An improved filter arrangement includes an HF inner conductor, an outer conductor arrangement inside which the HF inner conductor is arranged, and at least one stub line which branches off from the HF inner conductor at a connection point. The HF inner conductor and the at least one additionally provided stub line are arranged in a common outer conductor arrangement.