Integrated Duplexer Combining Quarter-Wave Transmission Lines

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Solution Overview

Problem

Cross-polarized antenna systems in telecommunication require complex circuits for RF signal transmission and reception, leading to increased manufacturing costs and testing time, with a need for reducing the number of circuits without compromising signal quality and reliability.

Innovation Solution

An integrated duplexer and combiner system using quarter-wave transmission lines to provide isolation and power splitting between receive and transmit signal paths, reducing the number of transmit filters and enhancing uplink diversity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If complex circuits are used for RF signal transmission and reception in cross-polarized antenna systems, then signal quality and reliability are maintained, but manufacturing costs and testing time increase

Engineering Contradiction:
Improvesignal quality and reliabilityVSAvoidnumber of circuits
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent combines the transmit filter and receive filters into a single integrated duplexer and combiner unit. The transmit filter is coupled to two receive filters through a transmission network that provides isolation between receive signal paths while simultaneously providing power splitting to transmit signal paths, reducing the total number of separate filter circuits required

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The transmission network performs multiple functions simultaneously: it provides isolation between the two receive signal paths and provides power splitting of transmitter power to two duplexed transmit signal paths. This multi-functionality reduces the need for separate dedicated circuits for each function

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

2Reliability

If multiple transmit filters are used in cross-polarized antenna systems, then signal transmission reliability is improved, but manufacturing costs increase

Engineering Contradiction:
Improvesignal transmission reliabilityVSAvoidmanufacturing cost
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent merges multiple filter functions into a single integrated unit where one transmit filter is shared between two transmit signal paths through the transmission network. This reduces the number of transmit filters from what would traditionally be required to just one, directly lowering manufacturing costs while maintaining signal transmission reliability through the isolation and power splitting capabilities of the transmission network

Inventive Principle:
Principle #5Merging (Combining)

3Reliability

If multiple transmit filters are used in cross-polarized antenna systems, then signal transmission reliability is improved, but testing and diagnosis time increase

Engineering Contradiction:
Improvesignal transmission reliabilityVSAvoidtesting and diagnosis time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

By integrating the transmit filter with two receive filters into a single duplexer and combiner unit, the patent reduces the number of separate components that need to be individually tested and diagnosed. The transmission network's isolation capability ensures that testing can be performed on the integrated unit as a whole rather than on multiple separate filters, reducing testing and diagnosis time while maintaining signal transmission reliability

Inventive Principle:
Principle #5Merging (Combining)

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 integrated duplexer and combiner system reduces manufacturing costs, simplifies troubleshooting, and improves uplink performance by increasing diversity, while maintaining signal quality and reliability.

Implementation Method 1

The transmission network includes first and second quarter-wave (lambda/4) transmission lines coupled between inputs of the two receive filters. A third lambda/4 transmission line couples the first and second lambda/4 transmission lines to an output of the transmit filter.

Methodology Applied
Scientific EffectQuarter-wave transformation:

Implementation Method 2

The two receive filters may have the same passband, while the transmit filter may have a different passband for FDD (frequency division duplexing) embodiment systems.

Methodology Applied
Scientific EffectImpedance matching:

Data Source

PatentEP3387707B1Integrated duplexer and combiner
Publication Date: 2021.06.30 HUAWEI TECH CO LTD
  • EP3387707B1 patent drawingFigure 1~2
  • EP3387707B1 patent drawingFigure 3~4
  • EP3387707B1 patent drawingFigure 5~6

AI summary

An integrated duplexer and combiner in a telecommunication system, such as a cross-polarized antenna system, is disclosed. An integrated duplexer and combiner may result in a reduction in the number of transmit filters used. A transmit filter may be coupled to two receive filters through a transmission network that provides isolation between the two receive signal paths and, at the same time, provide power splitting of transmitter power to two duplexed transmit signal paths. The transmission network includes first and second λ/4 transmission lines coupled between inputs of the two receive filters. A third λ/4 transmission line couples the first and second λ/4 transmission lines to an output of the transmit filter. The two receive filters may have the same passband, while the transmit filter may have a different passband.