Hybrid Duplexing Circuit With Adaptive Impedance Balancing

Solution Overview

Problem

Current duplexing solutions for wireless communications, particularly in LTE systems, face challenges such as increased complexity, size, and cost due to the need for multiple diplexing filters to support multiple frequency bands, and hybrid junctions suffer from impedance variations and limited isolation, leading to suboptimal performance and power loss.

Innovation Solution

An apparatus and method using a hybrid circuit with a variable impedance and a data store of impedance settings and calibration measurements, employing a system of equations to determine optimal impedance settings for improved isolation between input and output nodes, reducing the impact of manufacturing imperfections and allowing for adaptive impedance adjustments.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If multiple diplexing filters are used to support multiple frequency bands, then frequency band coverage is improved, but device complexity and size increase

Engineering Contradiction:

Improvefrequency band coverageVSAvoiddevice complexity

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent implements a single diplexing filter that can operate across multiple frequency bands by dynamically adjusting its characteristics. The filter is designed with tunable elements that allow it to adapt its resonance frequencies and impedance matching to different bands, eliminating the need for multiple separate filters for different frequency ranges.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The diplexing filter incorporates dynamic control mechanisms that allow real-time adjustment of filter characteristics. By varying the electrical characteristics of the filter elements through control signals, the filter can adapt its response to match different frequency bands, transitioning from a static to a dynamic system that serves multiple functions.

Inventive Principle:

Principle #15Dynamics

2Adaptability or versatility

If multiple diplexing filters are used to support multiple frequency bands, then frequency band coverage is improved, but manufacturing cost increases

Engineering Contradiction:

Improvefrequency band coverageVSAvoidmanufacturing cost

Core Design Contradiction:

Adaptability or versatilityVSEase of manufacture

Solution Approach 1:

The patent implements a single diplexing filter that can operate across multiple frequency bands by dynamically adjusting its characteristics. The filter is designed with tunable elements that allow it to adapt its resonance frequencies and impedance matching to different bands, eliminating the need for multiple separate filters for different frequency ranges.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent combines the functionality of multiple frequency-specific diplexing filters into a single unified filter structure. By merging multiple filter functions into one device with dynamic adjustment capabilities, the patent reduces the total number of components required, simplifying manufacturing and reducing costs.

Inventive Principle:

Principle #5Merging (Combining)

3Adaptability or versatility

If RF switching is used to select between frequency bands, then multi-band operation is enabled, but power loss increases

Engineering Contradiction:

Improvemulti-band operationVSAvoidpower loss

Core Design Contradiction:

Adaptability or versatilityVSLoss of energy

Solution Approach 1:

The diplexing filter incorporates dynamic control mechanisms that allow real-time adjustment of filter characteristics. By varying the electrical characteristics of the filter elements through control signals, the filter can adapt its response to match different frequency bands, transitioning from a static to a dynamic system that serves multiple functions.

Inventive Principle:

Principle #15Dynamics

Data Source

PatentEP3522380B1Apparatus for duplexing signals, wireless communications device and method of duplexing signals

Publication Date: 2020.12.02 U-BLOX

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AI summary

A duplexing apparatus comprises a reference of impedance settings and corresponding calibration measurements. A controller (128) is arranged to set a variable impedance (130) to a first impedance setting and transmit a first transmit signal at a first transmit frequency and measure a resulting first signal at an output node (116) of a hybrid circuit (114). The controller (128) then selects a second impedance setting, transmits a second transmit signal at a second transmit frequency and measures a resulting second signal at the output node (116). The controller (128) then determines a balancing result using a system of equations associating the first and second measured signals, and first and second calibration measurements from the reference in respect of the first and second impedance settings, respectively. A third impedance setting is retrieved from the reference by reference to the balancing result to provide isolation of an input node (112) from the output node (116) of the hybrid circuit (114).