Multi-band Filter Parallel Cavity Waveguide Design

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Solution Overview

Problem

Current satellite communication systems require multiple bandpass filters to handle various frequencies, but existing multiplexers do not function as effective multi-band filters, leading to inefficiencies and signal distortion due to mismatched filters and interference.

Innovation Solution

A multi-band filter design featuring a plurality of bandpass filters connected in parallel between input and output manifolds, utilizing cavity waveguide filters with symmetrical configurations and matching techniques to achieve high Q-factor performance and prevent signal distortion, allowing for efficient filtering across multiple passbands.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If multiple separate bandpass filters are used for different frequency channels, then each filter can be optimized for its specific band, but the overall system complexity increases and signal distortion occurs due to mismatched filters and interference

Engineering Contradiction:
Improvesignal qualityVSAvoidfilter configuration
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent combines multiple bandpass filters into a single integrated multi-band filter structure where several resonant circuits with different resonant frequencies are coupled to a common first and second conductor. This merging approach maintains the frequency-selective properties of individual bandpass filters while eliminating the need for separate filter components, thereby reducing system complexity and preventing signal distortion from mismatched filters.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The multi-band filter serves multiple frequency channels simultaneously through a single device structure. By incorporating multiple resonant circuits with different resonant frequencies that all couple between the same first and second conductors, the filter achieves multi-functionality, handling various frequency bands without requiring separate dedicated filters for each channel.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Productivity

If filters are closely packed to increase channel capacity, then productivity increases, but signal interference occurs leading to loss of information

Engineering Contradiction:
Improvechannel capacityVSAvoidsignal interference
Core Design Contradiction:
ProductivityVSLoss of information

Solution Approach 1:

The patent applies local quality by giving each resonant circuit its specific resonant frequency characteristic while they all share the same physical structure between first and second conductors. Each resonant circuit is locally optimized for its specific frequency band, allowing channels to be closely packed without interference because each circuit responds selectively to its designated frequency range.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The filter structure is segmented into multiple resonant circuits, each handling a specific frequency channel. This segmentation allows independent optimization of each channel's resonant frequency while maintaining a unified overall structure, enabling high channel capacity without signal interference between closely packed channels.

Inventive Principle:
Principle #1Segmentation

3Adaptability or versatility

If manual tuning screws are used to adjust filter frequencies, then adaptability is improved, but ease of operation deteriorates due to complex manual adjustment procedures

Engineering Contradiction:
Improvefrequency tuningVSAvoidfilter adjustment
Core Design Contradiction:
Adaptability or versatilityVSEase of operation

Solution Approach 1:

The patent incorporates variable capacitors in parallel with each resonant circuit, enabling dynamic adjustment of the resonant frequencies. This dynamic element allows the filter to be reconfigured for different frequency channels without manual mechanical tuning, improving ease of operation while maintaining adaptability through electrical control of the resonant characteristics.

Inventive Principle:
Principle #15Dynamics

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 multi-band filter effectively filters signals across multiple passbands with high Q-factor performance, preventing signal distortion and maintaining good in-band performance, thus enhancing the efficiency of satellite communication systems by closely packing channels without interference.

Implementation Method 1

The input manifold 12 is a linear waveguide, having a single input 12a. The manifold 12 has an end cap 12b terminating the waveguide. The waveguide input manifold 12 is dimensioned to guide microwave frequency (1 to 40 GHz) input signals.

Methodology Applied
Scientific EffectWaveguide: Waveguide (optics)

Implementation Method 2

The present invention is a multi-band filter, having a plurality of pass-bands. The multi-band filter is configured for use in a satellite system, preferably using cavity waveguide filters and waveguide manifolds to achieve a high Q factor.

Methodology Applied
Scientific EffectResonance: Resonance

Data Source

PatentEP2559098B1Multi-band filter
Publication Date: 2019.08.21 ASTRIUM LTD
  • EP2559098B1 patent drawingFigure 1~2
  • EP2559098B1 patent drawingFigure 3~4
  • EP2559098B1 patent drawingFigure 5~7

AI summary

A multi-band filter (10) comprising: an input manifold (12); an output manifold (18); and a plurality of filters (13, 14, 15, 16) connected in parallel between the input manifold (12) and output manifold (18). Each filter is directly coupled to a said input manifold and a said output manifold. The filters have a first section proximal to the input manifold which is coupled to the input manifold and a second section proximal to the output manifold which is coupled to the output manifold.