Electrochromic RF Phase Shifter with Impedance Transformers

Solution Overview

Problem

Existing high-frequency phase shifters using electrochromic materials are limited by inherently low achievable phase shifts, and cascading structures to increase phase shift result in increased structural complexity and insertion losses.

Innovation Solution

A radio frequency reflection type phase shifter utilizing electrochromic material-based variable capacitors connected through impedance transformers, where the characteristic impedances are selected to provide a phase shift proportional to the number of capacitors, allowing for greater phase shift with reduced insertion losses by optimizing the capacitance and reactance of the capacitors.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If cascading structures are used to increase phase shift, then phase shift is improved, but structural complexity and insertion losses increase

Engineering Contradiction:

Improvephase shiftVSAvoidstructural complexity

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The phase shifter is divided into multiple independent variable capacitor units (N capacitors), each contributing a proportional phase shift. This segmentation allows the total phase shift to be achieved through parallel combination rather than cascading, reducing structural complexity and insertion losses while maintaining the desired phase shift capability.

Inventive Principle:

Principle #1Segmentation

2Measurement precision

If cascading structures are used to increase phase shift, then phase shift is improved, but insertion losses increase

Engineering Contradiction:

Improvephase shiftVSAvoidinsertion losses

Core Design Contradiction:

Measurement precisionVSLoss of energy

Solution Approach 1:

The phase shifter is divided into multiple independent variable capacitor units (N capacitors), each contributing a proportional phase shift. This segmentation allows the total phase shift to be achieved through parallel combination rather than cascading, reducing structural complexity and insertion losses while maintaining the desired phase shift capability.

Inventive Principle:

Principle #1Segmentation

3Ease of manufacture

If varactor diodes are used as active elements, then circuit implementation is simplified, but non-linear behavior increases

Engineering Contradiction:

Improvecircuit implementationVSAvoidlinearity

Core Design Contradiction:

Ease of manufactureVSStability of the object's composition

Solution Approach 1:

The patent changes the fundamental parameter of the active element from varactor diodes to electrochromic material-based variable capacitors. This parameter change enables highly linear capacitance variation while maintaining ease of circuit implementation, as the electrochromic capacitors can be integrated into standard RF circuit topologies without significant modification.

Inventive Principle:

Principle #35Parameter changes

4Manufacturing precision

If electrochromic material is used, then capacitance values can be tailored and linearity is improved, but device complexity increases

Engineering Contradiction:

Improvecapacitance tailoringVSAvoiddevice complexity

Core Design Contradiction:

Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent changes the fundamental parameter of the active element from varactor diodes to electrochromic material-based variable capacitors. This parameter change enables highly linear capacitance variation while maintaining ease of circuit implementation, as the electrochromic capacitors can be integrated into standard RF circuit topologies without significant modification.

Inventive Principle:

Principle #35Parameter changes

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 proposed phase shifter achieves increased phase shift with lower insertion losses compared to traditional approaches, suitable for the microwave frequency range, and offers advantages such as tailored capacitance values and linear behavior.

Implementation Method 1

each of the variable capacitors comprises electrochromic material

Methodology Applied

Scientific EffectElectrochromism: Electrochromism

Implementation Method 2

each of the variable capacitors being connected to the coupler by at least one of the impedance transformers, the characteristic impedances of the impedance transformers having been selected so that the phase shifter provides a phase shift at least substantially proportional to the value of N

Methodology Applied

Scientific EffectImpedance transformation:

Implementation Method 3

each of the variable capacitors providing radio frequency reflection

Methodology Applied

Scientific EffectElectromagnetic reflection: Reflection

Data Source

PatentEP3319165B1A radio frequency reflection type phase shifter, and method of phase shifting

Publication Date: 2020.03.18 NOKIA TECHNOLOGIES OY

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AI summary

A Radio Frequency reflection type phase shifter is provided comprising a coupler for input and output, and Nvariable capacitors , where N is an integer value of 2 or more, each of the variable capacitors providing radio frequency reflection, each of the variable capacitors being connected to the coupler by at least one impedance transformer, the characteristic impedances of the impedance transformers having been selected so that the phase shifter provides a phase shift at least substantially proportional to the value of N, wherein each of the variable capacitors comprises electrochromic material.